Despite her many eccentricities she is extremely intelligent, scoring full marks in the practice exams. After travelling with her grandmother for some years, she returns to Japan to fulfill her promise to her brother to run an inn together. It is notable that Tsuruko is actually Motoko's biological sister as they are two of the few characters in the series who are siblings by blood relation the second siblings couple is presented by Kaolla and Amalla Su. Having traveled the world with Seta and Sara's mom, and it is hinted that a love triangle existed between the three at one point or at least that Haruka and Seta were romantically involved ; this is explored more fully in the manga, to the point that Haruka and Seta end up getting married. She is very intelligent, having placed top in the nation in the college practice entrance exams at their cram school. She is popular, beautiful but constantly tries to hide this as she studies to gain entrance to Todai. Mutsumi let him go for Naru's sake by deliberately losing a game of rock-paper-scissors to decide which of them would become Keitaro's wife deliberately losing a game of rock-paper-scissors is something she would do a second time in the manga during the mock wedding started to help her regain her memory after falling from a tree while she was trying to help Naru down from the tree , although she Mutsumi loved Keitaro and admits that she still loves him to Naru.