Komori was Honda's catcher since his earlier days as a little leaguer back when they were in Mifune Dolphins along with Sawamura and Shimizu. He continued to catch for Gorou when he returned from Fukuoka in Mifune Middle School but ended when Mayumura eliminated them single-handedly in their game with Kaidou Unified. In season 3 where Gorou left Kaidou and entered Seishuu, they become rivals where Gorou eventually won.
(Source: Wikipedia)