A few announcements have been made regarding the TV anime “Yahari Ore no Seishun Love Come wa Machigatteiru.” that is currently being aired on TV in Japan:
1. The anime will eventually cover up to the Cultural Festival Arc in volume 6 of the light novel.
2. There will be a spin-off episode with an original story and it will be broadcast in the week after the 12th episode is released, thus making the series 13 episodes in total.
3. A OVA with an original story will be made and bundled with the PlayStation Vita game “‘Yahari Ore no Seishun Love Come wa Machigatteiru.” which will be released in 2013 summer.
4. The original stories for the spin-off episode and the OVA will be written by Watari Wataru, the author of the light novel. This will be his first time writing a screenplay for TV anime.
Source: Tokyo Anime News