Daigoro's Tearful Decision! A Deadly Battle Between Itto and Retsudou with a Huge Explosion!

Ittou was to continue his journey with Yayoi. Komakine went to Retsudo. To his surprise, the request for an assassin for Itto was sent by Retsudo. When Komakine reported his conversation with Itto to Retsudo, he was poisoned and killed. What was Retsudo up to?