Satsujin Kippu wa Heart-iro
Genres: Mystery
Type: OVA, Episodes: 1
Aired: Feb 3, 1990
Studio: Deck
Source: Novel
Rating: PG-13 - Teens 13 or older
Synopsis:
A detective story about a murder on a train based on a series of young-adult novels for women by Yamaura Hiroyasu. Seiko, while suspended from school (she has been bullied) goes to Nagasaki, where she finds herself involved in a murder mystery. 

(Source: Shoujo &amp; General Weblog)