An anthology comic of Infinite Stratos by various mangaka.

A 4-koma anthology of the Toaru series.

"Unfortunately, your "ability to see the Dimensionless Number" has already awakened." "In the Interstice of Δt people are born, and then died there." A fragile-looking girl, jumping from atop building, on her back, for a moment, wings could be seen -- that is, the high-school student me, Saegusa Seiichi and Numerologist (Arcanist) Usagi Setsuna first meeting. One day, when trying the rumor of urban story about Red Hat who can grant any wish, my younger sister Manaka is kidnapped. Me who is frantically searching for her, suddenly can see floating infinite numbers tinged with noise out of nowhere. Action story of abilities of Numbers, kick off! (Source: Baka-Tsuki)

I began living by myself ever since I entered high school, and all of a sudden, my teacher Ms. Mitsuki proposed to me. Her hairstyle and clothing are different, but could it be that… she’s the woman living next door who I have a crush on!? But, how can we marry with this age gap! Even so, we began to date (tentatively)… “Pass me your keys. I’ll go make a duplicate.” “Huh!” Whether day or night, she barges in my apartment from next door, and flirts with me relentlessly in school whenever there’s a chance to! The girls in my class even almost found out about it—Ms. Mitsuki, are you serious about marrying me!? The love comedy of a beautiful and older teacher who lives next door and her student begins! (Source: Overlap, translated)

The story detailing the past of Senomiya Misaki, elder sister to the Robotics;Notes heroine Senomiya Akiho.