Fukuoka is an amazing place in Japan and a highly recommended destination to explore building your startup.
In fact, it is quickly becoming a global startup hub for Japan not just for business but also for travel (lots of places to visit, great food, great people, and very international).
Here are a few communities you can check out that are pretty good:
Fukuoka Growth Network (FGN) - They're one of the main communities for startups and entrepreneurship in the area.
Manabu Hubs - They're an international community for startups in Fukuoka with a focus on English.
CIC Fukuoka - They're a coworking space
Colive Fukuoka - They're more of a digital nomad community, but there are many participants who are startup founders. It's also a great place to find global talent.
Ramen Tech - They're a yearly conference / festival that attract a global audience.
BEAMSTART (that's us) - We have a growing English (international) community in Fukuoka, and we hold ocassional events (often times pegged to a larger conference)