Tenohira Size no Kimi ni Kiss

Yuito finally landed a job, only to get fired because of his large build. With no savings and unsure if he should return to his parents’ home, he runs into his childhood friend Tamotsu, who offers to let him stay over. When Tamotsu confesses he’s liked him since they were kids, Yuito feels happy and decides to take things further, kissing him, and before they know it, they end up sleeping together.

But the next morning, something completely unexpected happens to Yuito’s body… he’s shrunk down to a palm-sized doll! Even so, Tamotsu, now his boyfriend as well as his childhood friend, insists he’s adorable no matter what form he’s in!?

(Source: Gentosha Comics, translated)

Note: Includes one extra chapter.