Tenohira no Akira-kun

Shiori, an office lady, is in a terrible mood after breaking up with her boyfriend. She tries to forget about him, but finds herself unable to move forward and now she is in urgent need of healing! By chance, she stumbles upon Akira, a palm-sized high school boy. She finds him cute, like a small animal, and he does not even feel like a man. And she starts living with him...?

(Source: Shueisha, translated)