Let's do the Freaky Friday again
"Nanami is wonderful. So pure, noble, and beautiful... protecting the weak, despising evil; she's the personification of school justice! But I also know... about Nanami's true face."
When Mitsuru is hospitalized after saving Nanami from a runaway horse, Anthy and Utena find his diary which exposes all of Nanami's dirty secrets. As it turns out, past events did not play out exactly the way they seemed to.
"The Secret Nanami Diary" provides examples of:
- Call-Back: The plot of this episode is based entirely on references to previous episodes. It reveals that Tsuwabuki was present for all of Nanami's bullying schemes over the course of the series (even the ones before he was introduced,) and because he made a record of it now Utena and Anthy know about her underhanded tricks too.
- Don't Wake the Sleeper: Anthy breaks up a scuffle between Utena and Nanami by pointing out that Chu-chu is asleep...and he's making a such an uncanny yet gentle sound that they all stop what they're doing to listen.
- Embarrassing Animal Suit: Yamada, Tanaka and Suzuki wear cow costumes and graze with Nanami in the Plan no.2 Fantasy Sequence, a redux of when Nanami turned into a cow.
- "Freaky Friday" Flip: Further flipping within the context of the original Freaky Friday flip scenario. Yamada, Tanaka and Suzuki share plates of Anthy's curry with elephants and body-swap with them, creating a heretofore unmentioned implication that the elephants that accost Nanami and her posse in episode 8 were actually those three guys all along.
- History Repeats: The inciting incident of the episode revisits the Escaped Animal Rampage where Tsuwabuki and Nanami first met. He saves Nanami from being trampled by a runaway horse, but unlike the first time he doesn't make it out unscathed.
- Homework Slave: Willingly — Tsuwabuki doesn't just manage Nanami's schedule; he writes papers and makes cheat sheets for her.
- Human Disguise: In the shadow play, C-ko reveals herself to have been a monkey all along! And she is promptly caught by a monkey-catching robot and taken away in a Flying Saucer. Happy trails, C-ko.
- Indulgent Fantasy Segue: Tsuwabuki's plans start from events that occurred previously but conclude very differently. For example, Nanami implicitly gets into a traffic accident, wakes up in a hospital bed with Identity Amnesia, and Tsuwabuki is able to convince her that he is her big brother (never mind how much taller she is than him.)
- Innocuously Important Episode: On the surface this episode is a filler recap of the Nanami-centric episodes. But upon deeper inspection the episode reveals that there were several things going on in those episodes the characters and viewers weren't aware of at the time. This episode is indicating before the next arc that viewers have to be aware of how there were deeper, significant things going on in every previous episode and they will affect everything else moving forward.
- Let Me at Him!: Nanami is incensed after learning about Tsuwabuki's Plan No.1, and Utena has to hold her back so she can't lunge at him. While Utena is reading Plan No.2, Nanami holds Tsuwabuki back so he can't try to take the diary back and save himself from further embarrassment.
- Modesty Bedsheet: When Tsuwabuki's fear of being found out exceeds his fear of being seen without clothes, he wraps a bedsheet around him and begs Anthy to stop reading. She doesn't.
- Never My Fault: Utena points out remarkably calmly at several points that Nanami has been up to no good, but she deflects blame for the "Freaky Friday" Flip and claims she was a victim when her plans to make Anthy look like a weirdo failed.
- Noodle Incident: What, indeed, were Tsuwabuki's strategies for winning Nanami's heart? Especially Plan 24...
- Once More, with Clarity: A variation that recontextualizes events, but doesn't so much make them clearer as make them a more detailed sort of Denser and Wackier.
- Recap Episode: Instead of recapping the Black Rose arc, this episode specifically recaps Nanami's episodes. After all, most of the characters don't remember the Black Rose arc.
- Secret Diary: Right there in the episode title. Tsuwabuki's planner notebook for Nanami is part diary, revealing Nanami's Alpha Bitch schemes to Utena and Anthy, the two people most affected by her dirty tricks. It also reveals that Tsuwabuki's stalking skills are ninja-level, and his flights of fancy are even crazier than previously hinted at.
- Visual Pun: The episode has a doctor's office theme, and there are several visual puns based on equipment commonly found in exam rooms.Nanami: [Sitting on a weight scale] Who cares about the weight of Tsuwabuki's feelings? How about the weight of my feelings?
- Vomit Discretion Shot: In a new addition to the events of the ball in episode 3, Chu-chu drinks from a champagne glass, turns blue with nausea, and the familiar scene of Anthy getting sprayed with champagne serves as his discretion shot. When the action returns to Chu-chu, he is wiping down a woman's stained dress while sporting a big goose egg where she evidently bonked him.
- Waking Up Elsewhere: Multiple times.
- Tsuwabuki wakes up in the school infirmary without his clothes for reasons unknown. He is too embarrassed about being naked to keep Utena, Anthy and Nanami from reading all his secrets.
- Nanami wakes up with amnesia in the Plan no.1 fantasy sequence.
- Nanami wakes up again sporting a bandage on her forehead after falling out a window. No matter how much this seems like a Nested Story Reveal, it's a subversion. Tsuwabuki's secret diary is real, and really has those crazy plans in it.
- You Are Worth Hell: The sentiment expressed in Tsuwabuki's Plan No.2 Fantasy Sequence — if Nanami turns into a cow again, Tsuwabuki plans to turn himself into an ox so they can be together.
