Harmony by Mizutani Fuuka — Ongoing
A side story of 14-sai no Koi, following the age gap relationship between middle school student Nagai Tatsumi and Yuka Hinohara, his music teacher.
- Chapter 1 released Apr 9 '22
- Chapter 2 released Aug 5 '22
- Chapter 2.5: Intermission 1 released Aug 25 '22
- Chapter 3 released Dec 23 '22 Blushing Sports Swimsuits
- Chapter 3.5: Intermission 2 released Dec 30 '22 Blushing Swimsuits
- Chapter 4 released Apr 7 '23
- Chapter 4.5: Intermission 3 released Apr 27 '23 Blushing
- Chapter 5 released Aug 12 '23
- Chapter 5.5: Intermission 4 released Aug 18 '23
- Chapter 6 released Mar 21 '24
- Chapter 6.5: Intermission 5 released Mar 26 '24 Delinquent
- Chapter 8: [END] released Sep 6 '24