Takamiya Nasuno desu!

Spin-off manga centers on the daily life of Nasuno Takamiya, the "exceedingly airheaded" school tennis club member in Teekyuu, and her friends.
(Source: Anime News Network)
Note: Volume 2 contains the extra story "Maboroshi no Dai 1-wa: Kodaira Tasuku desu!" (幻の第1話 古平たすくです!).