The term touhou r34 refers to a specific category of fan-created content within the Touhou Project, a popular Japanese video game series known for its challenging bullet hell gameplay and unique characters. This content, often found on adult-oriented websites, features explicit and sexually suggestive depictions of the Touhou characters, particularly those with a more mature or mature-themed focus.

The Touhou Project, created by Team Shanghai Alice, has gained a dedicated fan base worldwide. While the original games are known for their difficulty and intricate gameplay, the fan-made content has expanded to include a wide range of genres, including visual novels, fanfiction, and artwork. The "r34" tag, short for "rating 34," is a common identifier for content that falls under the adult category, often featuring mature themes and explicit content.

One of the key benefits of this fan-created content is the ability to explore the Touhou universe from a different perspective. While the original games maintain a more serious and challenging tone, the "r34" content allows fans to engage with the characters in a more intimate and playful manner. This can include exploring the relationships between characters, their personalities, and their interactions in a way that is not possible within the confines of the main game series.