Hearty

From Hoshikuzuu Scans and Starry Sky Scans:

You lie. This is how you get through life without bumps. This is Honma’s skill. One day, while attending a university group meetup, he meets a student by the name of Ikai. He takes an interest in the serious and honest Ikai and decides to make him his next plaything and initiates contact. Suspicious, Ikai sets a one-month time limit for them to go out?