|Also Known As||Koutarou Shishigami|
|Occupation||Bodyguard at Club Primavera|
|First Appearance||Season 1|
During World War II, Leo served as a soldier in the Japanese army. He was primarily an instructor for new recruits, however, after the sudden surrender of the Japanese, Leo's return ship sank and he was captured by Allied forces. He was held in an Allied detention facility for three years until he was repatriated at the beginning of Rose Guns Days.
Leo appears as a lanky man with blue eyes and unkempt brown hair. He typically wears a red shirt with a popped collar and a loose-fitting black tie under a striped green suit.
Afterwards, Leo leaves the country to continue wandering.
Leo returns to Japan and meets Jeanne Amakawa. He introduces himself to her as "John" and the pair bond after defending several storefronts from Primavera's thugs.
Leo and Rose confront Richard and Cyrus in the church. The four reminisce about the beginning of their friendship before engaging in a shootout. Richard manages to escape. Cyrus and Leo begin an honorable fistfight, though it ends after Cyrus is shot and killed by Rose. Rose's faction celebrates its victory and Rose tells Jeanne that part of her plan involves Jeanne shooting her; she hopes to kickstart Jeanne's reputation as Madam by having her kill the "tyrant Rose." Jeanne hesitates but ultimately agrees.
In 2013, Jeanne reveals that Rose's death had been faked; in truth, she had quietly left District 23 with Leo. The two eventually married, with Leo adopting the name "Koutarou Hayashibara."
- Leo's outfit is derived from early designs of the card game Leaf Fight, which Ryukishi07 provided illustrations for.
- The first two characters of "Shishigami" (獅子) mean "lion" in Japanese. The decal on Leo's tie appears to be a lion's head. Furthermore, "Leo" is derived from the Latin word for lion.