A letter is delivered to Lord El-Melloi II informing him of a Clock Tower reunion. One morning, as the reunion's date draws near, Lord El-Melloi II takes a look in the mirror and reels in shock. He is suddenly a full decade younger! Lord El-Melloi II has become Waver Velvet, his former self! Believing himself to be in the grip of a powerful, magically induced delusion, Lord El-Melloi II immediately begins investigating how this could have happened. On the day of the reunion, he makes his way to the gathering of his contemporaries, planning to confront whoever transformed his body and hoping to reveal their intentions. However, when Touko Aozaki arrives, things take a sudden turn... (Source: Crunchyroll)

A great evil is sweeping over the realm; an evil that the young swordsman Roan and his life-long companion, the acolyte Yufa, must face head on! For these two travel toward their destiny, from the highest towers to the depths of the underworld, through forest and desert alike. With an ever-growing cast of fellow heroes, fate will grasp these travelers by their very souls and propel the band of skilled adventurers towards a noble end. Or ignoble, if they don't watch their step! Monsters are afoot and the way rife with danger and magic, the path forward may be unclear... But where will is strong, there is a way! Lessons wait in the depths of darkness, and good must prevail. The journey starts now!

Nearly twenty years into the 21st century, people have forgotten the existence of youkai. When a number of unexplainable phenomena plague adults of the human world with confusion and chaos, thirteen-year-old Mana writes a letter to the Youkai Post in search of answers, only to be greeted by Gegege no Kitarou...

Two OVA episodes featuring additional stories. Episode 0: Ritsu and Takano used to date back in high school, but broke up due to a misunderstanding. This is that story. Episode 12.5: Hatori and Chiaki go to visit the latter's family. It's really awkward in many, many ways.