Mature Woman: Rutting Ball-Play) aka Bowling Ball (たまもの, Tamamono) is a 2004 Japanese pink film directed by Shinji Imaoka.

The two meet when Aiko accidentally knocks Yoshioka off his bicycle, and they have a sexual encounter soon after.

Aiko begins preparing lunchboxes and giving them to Yoshioka at his workplace as a way of expressing affection, which she cannot do verbally.

Other than these points, Sharp judges the film typical of director Imaoka's work, which is known for its understatement in portraying relationships among characters on the outskirts of society.

Of Lunchbox, he writes, "The intensity of the love scenes and the tenderness of the performances make this work especially one of considerable potency.