I ♥ Mizuki. It's always such a thrill to hear Ishida as Mizuki. He doesn't have any appearances at Nationals, unfortunately. But the audio track made me very happy. XD
This is a partial translation of Mizuki and Yuuta's commentary from OVA 1.
[from 10:00 - just after Ojii gets smacked in the face with tennis ball]
Yuuta: Oh no...Mizuki-san! This is terrible!
Mizuki: Hrrrmm?
Yuuta: Aaaah!! That's the cake that everyone gave us! You're eating it all up now!!?
Mizuki: *stuffing face* What happened? You're making such a racket...
Yuuta: Th..that's right. Something terrible has happened on the court! Look!
Mizuki: Hmm? A fray, is it?
Yuuta: No! The player from Higa apparently smacked a ball into Rokkaku's coach!
Mizuki: It's alright, isn't it? That kind of wickedness is youthful and refreshing.
Yuuta: This isn't the time to be all relaxed about it! Or more like, what kind of old-man makes a comment like that? Ah?? That's--
Mizuki: That's...
Yuuta/Mizuki: Echizen Ryoma?
Yuuta: Echizen Ryoma...
Mizuki: What's HE doing here...?
Yuuta: So he's back in time for Nationals! Everyone, this is big news! Echizen Ryoma, the main character, has returned!
Mizuki: Che! As always, such awful timing. My long-awaited gala is ruined!
Yuuta: That Echizen, he's already picking a fight with the guys from Higa!
Mizuki: Well isn't that lovely. Go right ahead!
Yuuta: Or so we thought, but it looks like the match is going to continue.
Mizuki: Hmph. How disappointing.
Yuuta: Mizuki-san! Can't you make some more positive comments? If you don't, then the dark characters are all going to take over.
Mizuki: That's fine!! Ever since the city tournament, I have been marked as a bad guy character anyway! If it's going to be that way, then I'll portray a bad guy to the fullest!! Hahahahaha!!! *maniacal laughter*
Yuuta: Mizuki-san!! Ok, I understand! Please, don't swing a fork around!
Mizuki: Hnnggh!! *munch munch* This cake is delicious!
Yuuta: Mizuki-san...you've been a little unstable lately... ^__^;;;
Mizuki: And? What's been going on so far?
Yuuta: Er...Doubles 2, doubles 1, singles 3 and singles 2 - Higa has been winning by a big margin in all these matches. For singles 1, Higa's Kai and Rokkaku's Saeki-san are having a great match, but it seems that Saeki-san is feeling cornered now.
Mizuki: Hmph! Nationals was just too large an arena for a little school like Rokkaku after all.
Yuuta: That's not it! It's because the Higa team is using dirty tactics! Like aiming for the coach just a minute ago..
Mizuki: Look at the court carefully.
Yuuta: Eh? It looks like Saeki-san is making a come-back.
Mizuki: It might appear like they're on an equal playing field, but the winner is quite clear. Kai is going to win this one.
Yuuta: No... Saeki-san, come on! Aw....darn, he lost.
Mizuki: Fufufu... You are too lax. It wouldn't be exaggeration to say that this outcome was foreseeable from the singles 3 match. At a big tournament like this, no matter what your tactics, the first one who grasps the flow has the upper hand. And once that flow has been established, it is no easy feat to change it. In essence, the Rokkaku team was intimidated by the difference in power they were shown in the first match and subsequently were only dancing on the stage that Higa created.
Yuuta: Ooooh..
Mizuki: What is it?
Yuuta: It seemed like you weren't really paying attention Mizuki-san, but I guess you really were. That's the first commentary-like commentary you've said! Wow, you really are awesome!
Mizuki: *chuckles* So you've finally noticed! Very well. It's not too late...I'll be happy to hear your praises. So...!
Yuuta: Aaah!! There's still some cake left!!
Mizuki: -_____-## You certainly have some nerve...Yuuta-kun!