Ayumu-sensei to Hikaru-kun
Synopsis
Ayumu, a nursery teacher, finds a suspicious person at the nursery school where he works. However, the suspicious person turns out to be a popular actor named Hikaru Momose. Ayumu used to be a tutor for Hikaru, and they had promised to get married if Hikaru's feelings didn't change even after he became an adult?! (Source: Kadokawa, translated)