My Little, Stray Cat年下の惑い猫

"Keeping a cat is kinda scary... Cause it could leave at any time, right?" Mirei, a young OL always refuse drinking party invitations from her co-workers by using her "cat" as the excuse, although actually, the "cat" is the younger boyfriend she has been dating since her high school days. She always thought their daily peaceful life will last forever, until one night...