More from NPBT:
I watched Kikuchi pitch as much as I could during this year’s Koshien tournament. He does throw hard, during the games I watched his fastball ranged between about 87 – 96 mph (142-155 kmph). He did get a bit wild when throwing at the higher end of his range and I think he may have a tendency to overthrow at times. Perhaps this contributed to the back strain he suffered during the tournament. This video shows Kikuchi throwing his fastball mostly around 90mph, down in the zone with good command.
In addition to the heater, Kikuchi mixes in a slider and a curveball. He has good movement on both pitches needs to work on commanding them. During Koshien, he would go through stretches where he threw mostly breaking pitches; Goro Shigeno suggested at some point that he may have been trying to polish up his secondary stuff in anticipation of beginning his professional career.
He also has a goofy eephus pitch that I didn’t see him throw at Koshien.