Halloween is a beloved holiday preceding All Saints’ Day. Children usually look forward to trick-or-treating, and adults often attend Halloween parties in which the attendees dress up in costumes, enjoy good food, and listen to (often live) music.
On pixiv, the mood can be downright festive, with all sorts of Halloween-themed illustrations. Rice Shower (from Uma Musume Pretty Derby) and Long Island (from Azur Lane) are certainly cute in their costumes! What do you think of the others?