Mitsui Hisashi is two years older than Mito Yohei. When he won the MVP on behalf of Takeishi Junior High School, Mito was just a kid in the first grade of Wako Junior High School.
Mito Yohei was two levels below Mitsui Hisahi. When he entered Shohoku High School with the reputation of being a legendary delinquent junior high school student, Mitsui had already been a delinquent for a long time.
As the saying goes, if you don't fight, you don't know each other.