The “Seirai 10th Anniversary POP-UP SHOP,” celebrating the 10th anniversary of Seirai’s artistic career, will be held on the 8th floor of Yurakucho Marui from Thursday, September 10, 2026, through Wednesday, September 23, 2026! New merchandise, including Cheki-style cards and acrylic figures featuring original illustrations from *Gachikoi Nenchaku-ju: I Want to Be a Streamer’s Girlfriend* and *Ryoshiki Rei’s Theory of Ghost Marriage*, will be available. The event will also feature a signing session, COSMIC 2-shot photo sessions, and a giveaway of bromides plus a raffle for every 3,000 yen (tax included) spent.