Double full color cover page of uncensored Ch. 1.
"Time for School ~First... Period?~" was released on 11/1/12 as the first manga chapter of To LOVE-ru Revenge. It's included in Volume 1.
Summary
All the main characters are at school, now including a rehabilitated Nemesis. As first period approaches, several different characters face unfortunate encounters and complications.
Rito unknowingly stumbles into the girls' bathroom when Haruna walks out of a stall with her skirt and panties around her ankles. He finds himself unable to explain, and she finds herself too embarassed to attack him.
Nemesis finds Rito running out of the girls' bathroom, and flirts with him. He becomes uncomfortable, and Yui spots and disciplines them. Her lecture has no effect on Nemesis whatsoever, who seems to despise Yui's morals. Nemesis teases her about her look and body, humiliating her, even more so considering it's done in front of Rito. He attempts to comfort her, but she runs away.
Nana and Momo share a conversation about Rito with Momo trying to tell Nana he's really a "good" guy. As Nana seems to actually considers this as she remembers when Rito hugged her and helped her with Mea, the twins simultaneously have their periods, presumably for the first time. They avaid the several students asking if something's wrong as Momo seeks Rito for comfort and Nana leaves school to find comfort by herself.