FLIPFLOPs is a two-person team, with Takahata Yuki doing art and Ginko doing scripts. The Pixiv page and twitter we have on the Wiki page for ginko_(flipflops) both clearly say Takahata Yuki, and the Pixiv page says that Takahata is the one who does character design/storyboards/art. The About page on their website also says that Takahata does the art. The credits page in the 世界樹の迷宮II 〜六花の少女〜 manga by FLIPFLOPs also says Script: Ginko, Art: Takahata Yuki.
Updated by jxh2154