# Cosplay events in Ikebukuro, Japan

> Live situation record from CLSTR: https://clstr.news/situations/cosplay-events-in-ikebukuro-japan
> Updated: 2026-09-06T10:49:14.000Z. Sources: 8. Developments: 2.

Cosplay events in Ikebukuro, Japan, have seen significant activity and engagement in late 2026.

In early September, the Ultra acosta! 2026 event held at Sunshine City drew a record 24,000 attendees. The three-day festival, which ran from September 4 to September 6, 2026, included an all-night session, dance performances, and a flea market with 248 exhibitors. Due to the event's success, organizers announced a ‘New Year’s Eve All-Night acosta!’ scheduled for December 31, 2026.

Looking ahead to the end of the year, organizers have released details for the Ikebukuro Halloween Cosplay Festival 2026, set to run from October 30 to November 1. The festival will feature a cosplay parade with approximately 400 participants, a night-time photography experience for adults, and various specialized ticket options.

## Timeline

### 2026-09-06: Animate announces new merchandise for Nijisanji and Uma Musume Pretty Derby

Nijisanji's Shichigen Seitokai! is releasing a new album on November 11, 2026, while Uma Musume Pretty Derby launches a 47-prefecture themed merchandise collaboration at Animate.

7 sources. https://clstr.news/cluster/ultra-acosta-2026-draws-record-24000-attendees-in-ikebukuro

### 2026-09-06: Ikebukuro Halloween Cosplay Festival 2026 announces event details

The Ikebukuro Halloween Cosplay Festival 2026 will feature a 400-person parade and various themed events in Tokyo from October 30 to November 1, 2026.

3 sources. https://clstr.news/cluster/ikebukuro-halloween-cosplay-festival-2026-announces-event-details

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Cite as: Cosplay events in Ikebukuro, Japan. CLSTR, https://clstr.news/situations/cosplay-events-in-ikebukuro-japan