Negima!? Magister Negi Magi: Summer

The story begins Nodoka and Yue practicing casting spells. While training, Yue convince Nodoka that they casting a red string of fate spell on Nodoka. A spell which shows them whose their fate is. One end connect to Nodoka and the other end connect to Negi. Unfortunatly, this spell isn’t a fate connection, but it just connects two people with a red string. The rest is about how Nodoka and Negi spend the day trying to take their bath, while their hands are tie together.

Synopsis from Anime News Network