Sensui Arc

~ (In the dub) When Yusuke punches out Yanagisawa posed as Kuwabara, Yusuke goes through his whole theory on why he thought Kuwabara was the fake. He said that if they went after the weak one, Botan, he would never forgive them. Botan had tears in her eyes and she called him her hero.

~ While Kuwabara was fighting Mitarai/Sea Man, Genkai yells at Yusuke to go look for him, because Kuwabara's powers were sleeping and he can't use them. Yusuke runs off and Botan runs off with him to look for Kuwabara.

~When Yusuke died against the fight with Sensui, Keiko sensed Yusuke walking away from her. (Like so) Usually when Keiko does something involving Yusuke, its special, or vice versa. But Botan also sensed Yusuke walking away from her when she was in Reikai. (Like so)

Makai no Tobira

~ Before Yusuke jumps into the porthole, Botan asks Yusuke if he really had to go to Makai, she was all teary-like, and when he jumped into the porthole, she yelled out his name.

~When Botan and Koenma went to visit Yusuke in the Makai Tournament, the two were talking about Yusuke. Koenma wonders what Yusuke was going to do, and Botan responds by say "He is Yusuke... so he'll probably do nothing" (or something of that sort... Sorry, I got crappy subtitles...). It sounds like Botan knows Yusuke a lot...