Dokuganryū Masamune ~Sengoku no Arcadia Gaiden~

Dokuganryū Masamune ~Sengoku no Arcadia Gaiden~ is a web manga featured on Kakao Japan's Piccoma website. The series is written by Masaki Waji and illustrated by Anajiro.

Productions
Celebrating franchise creator Leiji Matsumoto's 80th birthday, the manga releases chapters every Wednesday.

Summary
Captain Harlock is caught in a super-gravity wave during battle against the Metanoids. Ending up in Earth's Sengoku era, he encounters the daimyo Date Masamune, the One-Eyed Dragon. Bearing a striking resemblance to the dying warlord, Harlock assumes his place to keep history on track while fighting against samurai resurrected by the Metanoids.

External Sources

 * Piccoma's page (Japanese)