Sunday Silence → Heart's Cry → Just A Way... three generations of gray coat enthusiasts.

Kurofune here is basically Heart's Cry's McQueen or Golshi. Well, closer to McQueen, since Heart's Cry kinda doesn't get along with most other horses with the sole exception of Kurofune, similar to how McQueen is for Sunday Silence.

Then again Kurofune gets along easily with other horses, with most other horses immediately taking a liking to him... other than noted gray coat hater Dream Journey.