My Little Lover - Minami Kun no Koibito

Once childhood sweethearts, high school seniors Chiyomi and Shunichi have drifted apart. One day, she realizes she still has feelings for him.

Wishing she were little again, Chiyomi is transformed into a miniature version of herself. When Shunichi finds her, she begs him to keep her hidden.

Shunichi takes Chiyomi shopping. They sneak into a local shrine where a legendary sacred mallet may be the key to solving her "tiny" problem.

Shunichi's mother and Chiyomi talk him into rejoining the kendo team for an important match. Meanwhile, a suspicious man snoops around his household.

Chiyomi sneaks out to get some doll dresses from her house. When she returns to Shunichi's home, she finds a mysterious couple who might be burglars.

Chiyomi secretly attends school but is seen by Riku. Later, Sayori stays over at Shunichi's house and sneaks into his room that night for a kiss.

Chiyomi is discovered by Shunichi's grandmother, who thinks she's a legendary princess. Later, she tries to fix a marital problem between her parents.

Tomiko is hospitalized after she suddenly faints. Shunichi is relieved to hear she's OK but soon has cause for worry when Chiyomi goes missing.

After questioning Shunichi, Riku finds out the truth about Chiyomi. Shunichi and Chiyomi leave on a trip to a hot springs to turn her back to normal.