Masaharu Tsuwabuki

Masaharu Tsuwabuki (石蕗 正晴 Tsuwabuki Masaharu) is a quiet boy who rarely talks to anyone, including his friends. In the beginning of the series, 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.

It is also revealed that on the night of a full moon, he will transform in his stuffed animal form in the evening and go back to being human in the morning, but on the night of a new moon, he will remain human for twenty-four hours, granting him some semblance of a normal life. Later in the series he confesses his love for Sumomo after discovering her feelings for him when he was in his doll form, unbeknownst to Sumomo. In the game version, Sumomo confesses her love to Masaharu. In Episode 9, he confesses that he is Nona Yūki, the stuffed animal and turns into a normal doll.

He is later changed back, but at the cost of the past five months of his memory which included all his adventures with Sumomo, unknown to her. It is soon discovered that once all the star drops are created, he will forget half of the year he spent with Sumomo, so on the last day before he takes the potion, he spends the night with Sumomo and ended it with a kiss. After taking the potion, he returns to his old self but he lost his memory as a side effect. However, although he doesn't remember the memory of the past few months, he remembered his feeling with Sumomo, thus saying that he will love her again even though his memory is lost.