Cardcaptor Sakura - Season 3 Episode 13

Sakura grows in magical strength and power for every Clow Card she transforms into a Sakura Card, while Yue's energy begins to falter. Yue also comes to the realization that Eriol is in fact Clow Reed and transforms in front of him. However, Eriol makes Yukito faint and erases his memory of him ever realizing who Eriol truly is; Clow Reed, since he is not yet ready to reveal himself and also reverses Yue's transformation back into Yukito. Syaoran, in the meantime, has fully realized his strong romantic feelings for Sakura and consults with Tomoyo, who helps him deal with his jealousy towards Eriol and gives him the confidence (just barely, though) to speak his mind to the oblivious Sakura. Before he can do so, however, both he and Sakura sense Clow Reed's presence once again, this time in the form of a basketball that leads them through the school at night.