 For health class, Ron has to take care of a sack of flour as if it were a baby, which proves difficult for him. Ron also finds out that his parents have adopted a baby girl, whom he immediately resents, referring to her as "the intruder." Also, Kim and Ron find out that Lord Monkey Fist has stolen a scroll containing instructions which could enable him to acquire a powerful ancient weapon. When they travel to Japan to stop Monkey Fist, Kim is concerned about Ron being reunited with Yori, the student ninja who was once romantically interested in Ron.