The world of Yozakura Quartet is actually not one, but two worlds: one of humans, and one of youkai. Despite appearing mostly human, youkai may have animal like physical traits, along with a number of special abilities. Normally youkai are confined to their world, but some have found their way into the realm of humanity. As a symbol of peace, and a bridge between the two realms, a city was constructed within the protective barrier of seven magical trees, otherwise known as the Seven Pillars. This city of Sakurashin is home to both humans and youkai, with the peace between them maintained by the Hizumi Life Counseling Office. The director of this office is Akina Hiizumi, a teenager with the inherited family ability to perform “tuning,” which can send harmful youkai back to their world permanently. He is aided by a group of girls, including the town’s 16 year old youkai mayor, Hime Yarizakura, their town’s announcer and resident telepath, Ao Nanami, and Kotoha Isone, a half-youkai who can summon objects just by stating the object’s name. As new residents enter and mysterious events begin to take place, this quartet of protectors and their closest friends must continue to guard the city of Sakurashin, and maintain the fragile balance of peace between humans and youkai.

Eiri Kurahashi is a Japanese art student who works in an antique shop. His friends begin to notice a dramatic, and rather concerning, change in Eiri, as he becomes more absent-minded and his behavior completely changes. They quickly decide to blame their friend's troubles on a girl. They may be right, however, as Eiri has begun seeing a beautiful, doll-like girl trapped within an antique Venetian glass that his uncle bought in France. She seems to be living in a strange other world, contained entirely inside this glass, but her image refuses to leave Eiri's mind. His sketchbook becomes filled with her likeness, and he realizes he has become completely infatuated with this strange little girl. When he recognizes her in a portrait by the mysterious Italian artist, Marchello Orlando, he learns her name is Cossette d’Auvergne, and that she was tragically murdered along with the rest of her family. One night, as he closes up the shop, he hears a voice asking him not to leave. Finally making contact with the object of his obsession, he makes a deal that he doesn't fully understand. [Written by MAL Rewrite]

Episode 2.5 of "A Summer Day's Dream" series of anime shorts based on the Touhou Project shooter game series.

Welcome to the fascinating world of Gensokyo, in which youkai (A term for all sorts of spiritual creatures), animals and some humans live, completely separated from our world by a magical barrier. The only gateway between the two worlds is the Hakurei shrine. Reimu Hakurei is the maiden working at said shrine. Whenever problems of supernatural causes (known as "Incidents") occur, Reimu goes out with her friends to investigate, eliminate the cause and hopefully restore Gensokyo to its equilibrium.