Ep. 21: Mayaka seeks Eru's help to improve her Valentine's chocolate while Houtarou investigates its disappearance
Aired on September 10, 2012

During their final year of junior high, Mayaka fails to win Satoshi's affection with homemade chocolates, a rejection he blames on the quality. Determined to succeed, she enlists Eru's assistance to create a superior batch. Concurrently, Houtarou observes Satoshi at an arcade, noting a decline in his usual competitive drive. After Mayaka leaves her new chocolate in the clubroom, it vanishes. Houtarou deduces the culprit and confronts Satoshi, who admits to taking it to avoid becoming obsessed with Mayaka, despite his feelings. Mayaka later confesses to Eru that she suspected Satoshi's involvement and recognized his fear of commitment. Eru thanks Houtarou for his assistance, and Satoshi contacts Mayaka to discuss their relationship.
Episodes
- Ep. 17 · Eru questions her actions as the Classics Club fails to protect the Hyouka manuscript from Juumoji.
- Ep. 18 · Houtarou investigates his teacher's survival of lightning strikes and helicopter concerns.
- Ep. 19 · Houtarou solves a fabricated mystery regarding counterfeit currency to prove his theoretical point.
- Ep. 20 · Eru and Houtarou get locked in a shed while visiting Arekusu Shrine for New Year's Eve
- Ep. 21 · Mayaka seeks Eru's help to improve her Valentine's chocolate while Houtarou investigates its disappearance
- Ep. 22 · Eru and Houtarou investigate a bridge construction disruption during the Hina Doll Festival procession.