Erika to Satoru no Yume Bouken

Two children, the girl Erika and the boy Satoru, live together in a small house somewhere in modern Japan. One day, before going to sleep, they notice a strange creature outside: it looks like a pink-white cat (Final Fantasy fans would immediately say: a moogle!), but talks like a human being. Before the mysterious creature disappears, it says only a short sentence: "Children! Find the Time Crown!". Without understanding what he meant by this, but realizing it must be something important, the two young heroes embark the next day on a dangerous journey - the quest for the power of the crown!

[From: MobyGames]