Tsuwabuki Masaharu♂

A quiet boy who rarely talks to anyone, including his friends. In the beginning of the game, he bumps into Sumomo Akihime, causing her to splash him with water. After the accident, he is inducted into the Gardening Club by Natsume Kisaragi. Later, he receives a mysterious beverage when he bumps into Arthur disguised at the time, who was carrying a bag full of potions, causing them to switch cans, which transforms Masaharu into a stuffed lamb doll. Kisaragi finds him and applies a second potion, allowing him to move and talk. In order to change back, he must work with his partner, "his chosen girl", who happens to be Sumomo. In order to change back, he must collect seven stardrops without telling her his true identity. It is revealed later on that the transformation potion is tied to phases of the moon. During the day he reverts to his human form, but just after sunset he changes to his stuffed animal form.

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[From Wikipedia]