Based on the same name manga by Itou Minoru, serialized in Kodansha's Weekly Shounen Magazine.

A detective story about a murder on a train based on a series of young-adult novels for women by Hiroyasu Yamaura. While suspended from school after beating up the seniors who bullied her best friend, Seiko goes for a trip to Nagasaki, where she finds herself involved in a murder mystery.
 
(Source: Shoujo & General Weblog)

Based on the romance manga "Koiko no Mainichi " by George Akiyama. 
Shinjuku gangster Sabu and his young wife Koiko try to live a normal life, despite the interferences of gang politics and criminal deals. After she saves his life, Sabu's gang-boss, Tominaga, falls in love with Koiko, and sends Sabu into increasing dangerous situations, hoping to cause his arrest, and thus obligate himself to "take care" of Koiko while Sabu is in prison. 
(Source: AniDB)

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