How about writing articles with other languages? There're many non-English speakers who are interested in blockchain games. You can ask the community to translate your articles.
And I think you should step up conventional SNSs more such as Twitter or Facebook, not only Steemit. I know that the game is based on STEEM but you can't attract new players if you're focused on Steemit too much. Those SNSs have hundreds or thousands times larger users than Steemit. Make a new Twitter account as the Japanese official Chibera account. I can assure you that many Japanese will be interested in it.