【Honda Technology】 Many High-Quality Outboard Motor Models Produced at Hosoe Outboard Engine Plant

Detailed technical explanations are available on the Honda technology site. Also check this.
https://global.honda/en/tech/Honda_Marine_DNA_4-stroke_outboard_motor_series/

While the small 2 HP to 6 HP models are produced elsewhere, Hosoe Outboard Engine Plant is responsible for production and global supply, including to Japan, of 21 outboard motor models*1 ranging from 8 HP to 350 HP. Of those, the 20 models up to and including 250 HP are all manufactured on a single production line.

*1. As of March 2024 / Small 2 HP to 6 HP outboard motor models are produced by Honda Power Products (China) Co., Ltd.