Although he has not thrown an MLB pitch in 2020, Yusei Kikuchi threw 2,628 pitches that were tracked by the PITCHf/x system in 2019, all of them occuring in the MLB Regular Season. In 2019, he relied primarily on his Fourseam Fastball (93mph) and Slider (86mph), also mixing in a Curve (75mph) and Change (85mph).
Basic description of 2019 pitches compared to other LHP:
His fourseam fastball has much less armside movement than typical and has slightly above average velo. His slider is thrown extremely hard and results in somewhat more groundballs compared to other pitchers' sliders. His curve has an exceptional bite and results in somewhat more groundballs compared to other pitchers' curves. His change (take this with a grain of salt because he's only thrown 6 of them in 2019) is basically never swung at and missed compared to other pitchers' changeups, has surprising cut action, is an extreme flyball pitch compared to other pitchers' changeups, is slightly firmer than usual and has some natural sink to it.