very similar to his Dead Leaves scene. I'd guess this is Suetomi

Honestly I thought it was Imaishi, but I imagine the share a similar style being (I suppose) coworkers for quite the time. If I remember well, in this episode there was Imaishi (seen in other clips here on Sakugabooru) but actually I remember directly GAINAX being mentioned in the episode credits... I think there was even the same Hideaki Anno, I dunno if directing or storyboarding this episode. And in fact this episode was pure gold xD To me it felt like seeing Abenobashi :)

I regret untagging my initial presume, this is indeed Shinji Suetomi, one of the cuts is pictured as a rough LO at the top right of this page from what I believe is 「彼氏彼女の事情・ミクロマン#26#39資料集」

https://twitter.com/onocan/status/872851024075042816?s=20

https://pbs.twimg.com/media/DBz9FQyUQAADqYM?format=jpg&name=4096x4096