Mysterious warriors appear to blast Miki into another dimension! She flees her captors only to find herself trapped in a world of monsters and madmen who plot the downfall of Earth. The only power that can possible save her (and the world) is that of the mysterious Mask of Zeguy. Miki must embark on a life-or-death quest for this talisman, with the villains who kidnapped in hot pursuit! (Source: AniDB)

Bundled with the 14th, 16th, and 17th volumes of the UQ Holder! manga.

The Otherworld is a vast and dangerous realm hidden from the knowledge of the common folk. It is also home to many creatures that threaten any human who dare visit it. To witness its desolate yet oddly absorbing environment, one must search for portals that could reside anywhere, from secret elevators to shrine entrances. After a fateful encounter with a horrendous Otherworld denizen, Sorawo Kamikoshi ponders whether to keep going or give up in life. Meanwhile, Toriko Nishina scours the Otherworld in hopes of finding her friend Satsuki, who she believes is lost somewhere within the realm. When the two cross paths, friendship blossoms. In order to acquire as much information about this obscure dimension, the two travel back and forth from the real world to the other. Sorawo and Toriko's bodies are soon influenced by the Otherworld, preparing them for the many horrors to come as both of them try to fulfill their goals.

Three high school girls are putting together a limited-time shop called PARK in Japan's Harajuku. One day, aliens come to Earth with the intent to steal the famed district's culture. At the same time, a mysterious girl appears. The three girls band together to defeat the alien threat and protect their beloved Harajuku. (Source: ANN)