OK, given the fact that Kakyuusei OVA and TV Serie are based on the same female characters, Pink Pineapple decided to "switch" the maing guy for the sake of the story. There are, obviously, differences between the OVA and TV Serie, but the emphasis here on the main character.

Granted, they are almost all alike: they live in an apartment (it even looks the same apartment with a poster of Doukyuusei 2's Yui!), both works part-time at Dogeza Cafe, both attend Uzuki Gakuen, both best friend is Minoru, both are classmate of Mizuho, hence, senpai of Ai.

Their differences lies on their personality. I think Tooru is a bit more free going than Tsuyoshi. In the OVAs, Tooru goes to date other girls (namely Ai), even when he knows that Miko was bringing him lunch in Mizuho's home. On the other hand, Tsuyoshi is more inclined to do things right, although he will sometimes fail, even if it is not his fault. However, this comparison isn't totally fair, The OVA only focused on Mizuho, Miko and Ai. If Tooru (and, hence, the OVA) were given more emphasis on other characters, such difference may not be evident.

Now, if I were to choose which of those two I would like to be, I will definitely choose Tsuyoshi. Hey, it wasn't difficult, given that my favorite girl is Mahoko!

Note: All images and characters are copyright of Elf, KSS Studios, and Pink Pineapple. They are being used without permission.