Hiroto started baseball early when he played catcher for his school's team in his first grade.

He specialized as a pitcher in junior high, and helped his team win championships and runner ups in his hometown's local tournaments.

[1][2] He then went on to become the ace pitcher of Suma Shofu High School, where in his 2nd year, he led the team to win runner-up in the prefectural tournament.

[8] Standing at 189 cm, Saiki is a right-handed pitcher whose arsenal consists of fastballs clocked at a maximum of 157 km/h, sliders, curveballs and splitters.

[10] He aims to follow the footsteps of his teammate and fellow high-school draft Shintaro Fujinami who is known for his high velocity pitches.