So when does the Yukata Festival event end?

[Hiashi]

I can't seem to find an end date for the event. If anyone knows please tell me.

The reason is that I've been putting off obtaining some of the accessories because I want to wait until the effects on my current ones run out but I don't want to wait too long and have the festival end without notice.

[Megu]

Hello Hiashi. You can check the girl npc beside the portal to the Onigashima festival. She's named like Guide okuni or something. I haven't been online lately so I forgot, I think the event ends on mid-September.

[Hiashi]

Yeah you're right. She says it ends on September 23.
Though CS could have mentioned it on their website as well.