Ep. 4: Jun invites Kaoru and Sentarou to join a quartet for a Christmas gig with only one month to prepare.
Aired on May 4, 2012

4
Brother Jun invites Kaoru and Sentarou to join a quartet for a Christmas performance at a jazz bar, leaving them just one month to prepare. During this time, Kaoru struggles with self-pity and jealousy toward Sentarou, believing his friend has everything he lacks. However, his perspective shifts dramatically when Sen reveals the secret of his birth. This revelation helps Kaoru recognize the insignificance of his own misery compared to the truth he has uncovered, altering his emotional state regarding his relationship with Sentarou and his own circumstances.
Episodes
- Ep. 1 · Kaoru visits a record store and clashes with Sentarou over musical styles.
- Ep. 2 · Kaoru joins an impromptu jazz quartet and accepts a study date with Ritsuko.
- Ep. 3 · Sentaro's First Love and Kaoru's Picnic Deception
- Ep. 4 · Jun invites Kaoru and Sentarou to join a quartet for a Christmas gig with only one month to prepare.
- Ep. 5 · Kaoru Seeks Ritsuko's Response on Romance Before Visiting His Mother in Tokyo
- Ep. 6 · Sentarou feels isolated in a new class while Kaoru grows jealous of his friendship with Seiji.
- Ep. 7 · Sentarou and Kaoru face widening distance during school festival preparations
- Ep. 8 · Ritsuko questions her feelings for Sentaro while Junichi attempts to deter Yurika