From Kyoka Mid, Kobayashi Masanari a.k.a. Masa is Katou Hideyoshi's right hand man and best friend. Also a senior at Suzuran in Hana's first year. During his last year in Suzuran, Masa was attacked by a Housen student, leading Hideyoshi to take revenge for his sake. He have an old rivalry with Andou. Masa became one of the top of Suzuran and the second in the Hideyoshi Faction. One day he was surprise attacked by Urano from Housen. These events are considered the spark that started the war between Suzuran and Housen. At the tail-end of the war, when King Joe was about to attack an already-downed Hideyoshi, Masa stepped in and stopped Joe from attacking his fallen best friend. This, in turn, sparked the all-out war between the Housen and Suzuran forces, all of whom were quietly waiting in the shadows during the five one-on-one matches.

As Hideyoshi's right hand man, he was seen as both strong and fearsome, many unwilling to fight against him not only due to his strength, but the wrath that would be invoked by Hideyoshi after he was defeated. Although not seen fighting often, Masa was a vigorous man, living up to his position of right hand man with relative ease through defeating many people almost effortlessly. His relationship with Hideyoshi was a close one, and together they were seen as one of the scariest duos at Suzuran during their time as seniors.

Left for Tokyo with Hideyoshi when they graduated.