Notes:

Jun Yamazaki taking credit for the illustration.

Some unnamed characters that I could identify:

• The octopus from the ED 1.
• The bystander that thinks that Wakana and Marin are a couple, and proceeds to hear Gojo talking about his experience playing MoiGirl (Episode 3).
• The first guy who takes pictures of Marin's Shizuku Kuroe cosplay (Episode 5).
• The bird that takes their food during the beach date (Episode 8).
• The lady that meets Gojo and Kitagawa in the elevator after their time in the love hotel runs out (Episode 11).