ok in this episode it truly shows that Tsukasa isn't as bright as you think he is. He tells Tsukushi that she and his sister are as different as Light and day. Tsukushi corrects him saying the saying is night and day. Lol it's hilarious, he makes mistakes like that all the time. In the manga he does it quite often, its so funny considering you would think he was smarter.
Tsukasa: (after Tsukushi's makeover) I think I've proven that a girl like you can be made to look beautiful if she's given the right treatment.
Tsukushi: Now hold on. What exactly are you trying to say? I don't need your beauty treatments. What the hell were you thinking! What an you are idiot!
Tsukasa: Look would you stop being so sensitive for a minute? I'm willing to give in here. I've decided that I'm going to allow you to hang out with me. Of course you'll never be as much fun as my sister was.
Tsukuchi: (after reading the blackboard) I have not slept around with anyone in my life so how could I possibly have a baby!
Tsukasa: (blushing) She came to tell me she's still a virgin. She wanted me to know she's not seeing anyone else. I think she likes me she really likes me.