For the crime of rape by sexual intercourse through penile penetration to be consummated, the penis must penetrate the cleft of the labia majora (also known as the vulval or pudendal cleft), even in the slightest degree; mere touching or grazing of the external surface (mons pubis or fleshy part of the labia majora) without penetrating the cleft only constitutes attempted rape or acts of lasciviousness, depending on intent.

The case arose from allegations of repeated sexual abuse committed by the accused-appellant, Efren Agao, against his minor stepdaughter, AAA, starting when she was 10 years old in 2009/2010 and continuing until 2012. Agao lived with AAA and her mother, BBB. The specific charges relate to incidents in July 2010 and January 2012.

• Accused-appellant Efren Agao was the stepfather of the private complainant, AAA (born December 6, 1999).
• AAA alleged that appellant first abused her in 2009 (age 10) by touching her private parts while bathing her.
• The first rape charge stemmed from an incident in July 2010 (AAA age 10), where AAA awoke to find appellant touching her breasts and vagina, undressing her, mounting her, and trying to insert his erect penis, managing to introduce it into the outer fold (labia majora) despite her fighting back.
• The second rape charge stemmed from a similar incident in January 2012 (AAA age 13), where appellant again attempted penetration while she slept but was unable to fully penetrate because she resisted.
• AAA did not immediately report the abuse, fearing disbelief and potential harm to herself and her mother.
• AAA reported the abuse in June 2014 after she and her mother left the appellant; she eventually filed a complaint with police assistance.
• A physical examination by PCI Jocelyn P. Cruz revealed no evident injury or hymenal laceration, which PCI Cruz opined could be because the incidents happened years prior and any injuries could have healed, or if the penis only touched the labia.
• Appellant denied the allegations, claimed he treated AAA like his own daughter, and suggested the charges were fabricated by AAA's biological father, CCC.
• The RTC and CA found AAA's testimony credible, consistent, and straightforward, establishing that appellant's penis touched AAA's labia.

• Accused-appellant Efren Agao (petitioner before the Supreme Court) argued that the prosecution failed to prove consummated rape beyond reasonable doubt, as his penis merely touched the external genitalia.
• Agao contended that AAA's testimony was incredible and inconsistent.
• Agao argued that the significant delay in reporting the alleged incidents cast doubt on the veracity of the charges.

• The People of the Philippines (respondent before the Supreme Court) argued that the RTC and CA correctly gave credence to AAA's positive and categorical testimony.
• The People maintained that appellant was properly found guilty of consummated rape, as jurisprudence holds that mere touching of the labia by the penis is sufficient.
• The People sought affirmation of the CA decision, including the modified damages.

• Did the Court of Appeals err in affirming the Regional Trial Court's conviction of the appellant for two counts of rape?
• Does the mere touching of the labia majora by an erect penis constitute consummated rape, or is some degree of penetration into the vulval cleft required?

• The Supreme Court dismissed the appeal and affirmed the conviction with modification: appellant is guilty of one count of Statutory Rape (Crim. Case No. 1453-V-14, victim aged 10) and one count of Simple Rape (Crim. Case No. 1454-V-14, victim aged 13), sentencing him to reclusion perpetua for each count.
• The Court upheld the credibility of AAA's testimony, finding it sufficient to establish that appellant's erect penis made contact with her external genitalia ("outer fold," "sa may gitna," "sa may hiwa") in a manner consistent with consummation under the clarified standard.
• The Court clarified the anatomical threshold for consummated rape by penile penetration: it requires the slightest penetration of the penis into the cleft of the labia majora (vulval cleft), not just contact with the external fleshy surface. AAA's description met this clarified standard.
• For pre-puberty victims (defined generally as under 9 years old based on medical literature), the Court introduced a calibrated standard where consummation is deemed met if evidence shows a clear physical indication of the inevitability of penetration (e.g., repeated touching of erect penis on genitalia) but for the victim's physical immaturity/resistance.
• The Court reiterated guideposts for appreciating child victim testimony, emphasizing circumspection regarding inherent limitations without demanding unreasonable precision, and considering attendant circumstances like pain or bleeding.
• The Court noted the non-appreciation of the stepfather relationship as a qualifying circumstance was correct as marriage wasn't proven, and the Information didn't allege a common-law relationship.
• The Court called upon the Legislature to review the penalties for attempted rape vis-a-vis acts of lasciviousness and lascivious conduct under RA 7610, noting a potential distortion where attempted rape carries a lighter penalty despite greater criminal intent.

• Consummation of Rape (Penile Penetration): Defined as the slightest penetration of the penis into the cleft of the labia majora (vulval or pudendal cleft). The Court explicitly clarified that prior jurisprudential references to "mere touching" or "entry into the lips of the female organ" must be understood as requiring this minimal penetration of the cleft, not mere epidermal contact on the external surface. Applied here to affirm consummation based on AAA's description of contact "sa may gitna/hiwa" (middle/slit).
• Attempted Rape: Defined as the commencement of the commission of rape by overt acts (e.g., positioning, attempt to insert penis) without achieving the slightest penetration of the vulval cleft. Distinguished from consummated rape based on the lack of penetration into the cleft.
• Statutory Rape (Art. 266-A(1)(d) RPC): Rape committed when the offended party is under the statutory age (then 12, now 16 under RA 11648), irrespective of force or consent. Applied to the first count as AAA was 10.
• Simple Rape (Art. 266-A(1)(a) RPC): Rape committed through force, threat, or intimidation when the victim is above the statutory age. Applied to the second count as AAA was 13 (above the then-applicable age of 12) and the act itself implies force/intimidation against a minor.
• Credibility of Minor Rape Victim Testimony: Courts generally lend credence to the testimony of young rape victims, as they are unlikely to fabricate such humiliating experiences unless true. Applied to uphold AAA's testimony despite delay and lack of physical evidence.
• Circumspection in Appreciating Child Testimony: While adhering to the Rule on Examination of Child Witness, courts must appreciate such testimony with sensitivity to the child's inherent linguistic and cognitive limitations, avoiding demands for overly precise anatomical descriptions, and considering attendant circumstances (pain, bleeding, redness, etc.) as corroborative evidence of penetration. Discussed extensively to guide lower courts.
• Physical Evidence in Rape: The absence of physical findings (e.g., hymenal laceration, semen) does not negate rape, especially when considerable time has passed, as injuries can heal. Applied to dismiss the significance of the negative medical exam results.
• Appeal Opens Entire Case for Review: An appeal in a criminal case throws the entire case open for review, allowing the appellate court to correct errors even if unassigned. Implicitly applied as the basis for the SC's comprehensive review and clarification.

• "In the crime of rape through penile penetration, a particular physical situs and threshold penile contact draws the line between attempted rape and consummated rape... the Court here clarifies that rape of a female victim by a male person through penile penetration reaches the consummated stage as soon as the penis penetrates the cleft of the labia majora, also known as the vulval or pudendal cleft, or the fleshy outer lip of the vulva, in even the slightest degree."
• "Stated differently, the Court here elucidates that 'mere touch' of the penis on the labia majora legally contemplates not mere surface touch or skin contact, but the slightest penetration of the vulval or pudendal cleft, however minimum in degree."
• "On the unenviable task of determining at which stage the crime of rape was committed, the courts are further enjoined to be circumspect in their careful appreciation of the language used to recount the manner, degree of penile contact, especially when the victim attesting to the same is a minor child."
• "For child victims in the pre-puberty age, the genital contact threshold for a finding of consummated rape through penile penetration is deemed already met once the entirety of the prosecution evidence establishes a clear physical indication of the inevitability of the minimum genital contact threshold as clarified here, if it were not for the physical immaturity and underdevelopment of the minor victim's vagina..."
• "Rape is a crime because it is a violation of a person's consent to intimacy and sexual relations. Rape is a crime because it is a violation of a person's human dignity. No amount of anatomical discourse should ever erase the heinousness of this crime." (From J. Leonen's Dissent, but captures a sentiment echoed implicitly in the ponencia's context)

• People v. Orita (1990): Established that perfect penetration/hymenal rupture is not needed for consummation; slightest penetration suffices; questioned the existence of frustrated rape. Referenced as the start of the Court's refinement of the stages of rape.
• People v. Dela Peña (1994): Ruled that mere touching of the vagina by a penis capable of penetration is consummated rape, within the context of an erectile penis capable of full penetration. Cited as refining the definition of "touch."
• People v. Escober (1997): Held entrance or introduction to the labia of the pudendum is fundamental. Cited as part of the evolution of the doctrine.
• People v. Castromero (1997): Found consummated rape where penis merely touched ("lumapat") the minor's private parts, citing Dela Peña. Cited as appreciating "lapat" (touch/press) as sufficient contact.
• People v. Quiñanola (1999): Reiterated that "mere touching" by a penis capable of consummation constitutes carnal knowledge. Referenced for the "mere touching" standard.
• People v. Campuhan (2000): Clarified "touching" requires penis touching the labia or sliding into the female organ, not mere stroking of external surface (mons pubis); emphasized labia are beneath the mons pubis, thus touching them implies some penetration. Cited extensively for attempting to define the required "touch" and distinguishing it from surface contact.
• People v. Ombreso (2001): Found consummated rape where erect penis "touched the upper part of complainant's vaginal opening" despite no full penetration. Cited as appreciating contact with the "vaginal opening."
• People v. Comanda (2007): Held briefest contact or mere introduction to the aperture/labia consummates rape. Cited for the "briefest contact" standard.
• People v. Francisco (2001) & People v. Mariano (2001): Required proof that the penis entered the labial threshold; lack of proof led to attempted rape conviction. Cited as cases requiring ascertainment of entry into the labial threshold.
• People v. Tolentino (1999), People v. Arce, Jr. (2001), People v. Dimapilis (2000), People v. Quarre (2002), People v. Brioso (2009): Cases where convictions were downgraded to attempted rape due to perceived lack of proof of penetration, despite testimony of attempts to insert/contact. Cited as examples of "diverging cases" where similar factual descriptions were treated differently, highlighting the need for clarification.
• People v. Besmonte (2014): Cited by the RTC to support that carnal knowledge doesn't require full penetration and touching the labia/pudendum suffices.
• People v. Jurgueta (2016): Cited by the CA regarding the appropriate amount of damages.
• People v. Manggasin (1999): Cited by the CA regarding the non-appreciation of the step-parent relationship if marriage is unproven.
• People v. De Guzman (2018): Cited regarding the review standard in criminal appeals and the presumption of innocence.
• People v. Salinas (1994): Cited in Escober for the principle that partial penetration is as serious as full penetration ("bombardment of the drawbridge").
• People v. Banzuela (2013), Cruz v. People (2014): Discussed in the context of distinguishing attempted rape from acts of lasciviousness based on "intent to lie" (intent to penetrate).

• Revised Penal Code (RPC), Article 266-A (as amended by R.A. 8353): Defines the crime of Rape (both through carnal knowledge/penile penetration and sexual assault). Paragraph 1 (carnal knowledge) and its circumstances (a - force/intimidation, d - victim under 12) were directly applied. Paragraph 2 (sexual assault) was discussed by analogy.
• Revised Penal Code (RPC), Article 266-B (as amended by R.A. 8353): Prescribes the penalty for rape (reclusion perpetua under relevant circumstances). Applied in sentencing.
• Republic Act No. 7610 (Special Protection of Children Against Abuse, Exploitation and Discrimination Act): Mentioned in the Information as being violated in conjunction with the RPC articles. Also discussed regarding penalties for lascivious conduct under Sec 5(b) vis-a-vis attempted rape.
• Republic Act No. 11648 (Act Increasing the Age for Determining Statutory Rape): Mentioned as having further amended Art. 266-A (raising age to 16) and redefining rape neutrally ("person" instead of "man"/"woman"), though not applicable retroactively to this case.
• A.M. No. 00-4-07-SC (Rule on Examination of Child Witness): Discussed extensively regarding the need for courts to appreciate child testimony with sensitivity and circumspection, recognizing its inherent limitations, beyond just facilitating the testimony itself.
• RPC, Article 6: Defines Consummated, Frustrated, and Attempted felonies. Implicitly applied in discussing the stages of rape.
• RPC, Article 51: Penalty to be imposed upon principals of attempted crime (two degrees lower). Applied contextually regarding penalty differences.
• RPC, Article 336: Defines Acts of Lasciviousness. Distinguished from attempted rape.