Resident historian of the Touhou series and ninth (and current) incarnation of the "Child of Miare", possessing a photographic memory as well as the ability to recall memories from her previous incarnations (Aichi, Ani, Ami, Ayo, Ago, Amu, Anana and Aya). In-universe author of Perfect Memento in Strict Sense and Symposium of Post-Mysticism, encyclical works on the various faces, places, and dates in Gensokyo. Also writes mystery fiction under the pen name Agatha Chris Q. Her original, "zeroth" incarnation was the author Hieda no Are, writer of the Kojiki.
After it was revealed that all Children of Miare generally live for around 30 years in Strange Creators of Outer World, some fans began to count the days until Akyuu's 30th birthday, which would be, according to Perfect Memento, around August/September 2024 (earliest August 7, latest September 6). However, ZUN has confirmed that Akyuu wouldn't die, and that the other characters wouldn't grow old, as the series runs on 'Sazae-san time', a floating timeline (commonly called "Comic Book Time" in the west due to its heavy use in that media). This didn't stop fans from awaiting the day. Around August 7th, 2024, fans across the world began discussing the death of Hieda no Akyuu.
