That song is called "Here we are again", let's call it that.

In fact, this song has never been released, it is just adapted from a song in "Long Vacation".

"Long Vacation" (ロングバケーション) is a love TV series written by Kitagawa Etsuko and starring Kimura Takuya, Yamaguchi Tomoko, Takenouchi Yutaka, Inamori Izumi, Matsu Takako and others.

The play tells the story of a romantic sibling love story between a has-been female model and a talented young pianist.

The play was broadcast on Japan's Fuji TV from April 15 to June 24, 1996.