"A Tiny Heart, Crimson Heart"
"After a flight accident with their new-year flight on broomstick, Chocolat and Vanilla found themselves...in Akira's house, with a little boy who turns to be Akira's cousin. Aside from being attracted to the new year celebrations of the human world, Chocolat noticed that...the little boy's heart is glowing...red, VERY red! "
(info from Wikipedia)
