If you're looking for anime similar to Kusatta Kyoushi No Houteishiki, you might like these titles. All recommendations are made by Anime-Planet users like you!
During a much needed vacation in England, American cops Dee Laytner and Randy McClane find out that danger has found them yet again. Their hotel, it seems, is under investigation for a series of murders which cannot be solved, perplexing local authorities and visitors alike. Now, Dee's clever plans to take Randy's virginity must be stalled in lieu of the investigation, since hesitation might cost both of them their lives!
Misaki Takahashi has little hope of getting into a university, so his older brother Takahiro's friend, Usami Akihiko, offers to tutor Misaki as a favor to Takahiro - for Usami is secretly in love with him. However, as time passes Misaki realizes that he has uncomfortable and budding feelings for Usami. Meanwhile, Hiroki is a man who can't get over an unrequited love with Usami in the past - and with the help of Nowaki, he may finally learn to love again. These couples and more experience the joys and sadness of love between men under the most unlikely conditions.
Though Junjou Romantica is a bit more focused on forced advances, both it and Kusatta have a similar comedic and lighthearted feel. Love triangles abound in both, and since you clearly are into shounen-ai, you'd surely like one if you liked the other.