Itsuki-kun ga Osewa ni Narimasu

Chronological release order: 1) Itsuki-kun ga Osewa ni Narimasu: Itsuki learns a lot of new useful life skills thanks to his role models, Umi and Riku. 1.1) [Shuiro ni Yokujou](https://www.mangaupdates.com/series.html?id=177841) 1.2) [Futago-kun no Seitsuu Jijou](https://www.mangaupdates.com/series.html?id=159708) 2) Itsuki-kun no Kimochi: The story is about the two twins, Umi and Riku, who will have a lot fun with their little friend Itsuki once again!