|The Second Hero Diary|
|Romaji||Ni-satsu-me no Yūsha Gyoki|
|English||The Second Hero Diary|
|Release Date||Japanese - June 27, 2015|
|← None||Sprouting →|
Meanwhile, Inubouzaki Fu is pondering over which of the second-year students would be best suited for Hero Club president after she graduates. After considering each of the upperclassmen, she and Inubouzaki Itsuki conclude that Karin is the best fit for the job.
Unnerved by all she had learned through her experiences as a hero, Sonoko makes frequent visits to the Taisha to gather information; however, all they can offer her is vague plans for the future of the Hero System. Curious to look into the past for answers, she enlists the help of the Hero Club. Together, the six of them go to Sonoko's house and begin digging through history books from the Nogi family archive.
After organizing the piles and stacks of books, the girls begin searching through them. Yuki Yuna takes a book off a bookshelf and finds that it contains a lot of redacted text. There are many other books just like it, and Togo Mimori finds one inside an encyclopedia from the Christian Era that contains the words "Hero Diary". Bewildered, the girls closely inspect the diary's pages and find a photograph and the author's name: Nogi Wakaba. Upon hearing the name and seeing the photo, Yuna goes into a trance.
"The Passed Baton" Edit
Once Yuna is snapped back into reality, she tells the others that she remembers Wakaba from her time spent unconscious after the last Vertex battle. She says that Wakaba called out to her, and the two of them met. The others are perplexed but do not consider it out of the realm of possibility.
The six of them continue to skim through the book, looking for more text that escaped censorship. They discover the names of some of the Christian Era heroes, including Takashima Yuna. Yuna wonders if she has a deeper connection with the former hero, and Sonoko explains that the name "Yuna" was once special, bestowed upon girls who perform a certain gesture at birth. The girls conclude that although much of the diary is redacted, it is clear that life was not easy for the Christian Era heroes, and that they should be grateful for their predecessors' sacrifices.
Later that evening, Togo and Sonoko discuss how the diary was censored multiple times over the years, and how it is indicative of the Taisha's disposition for information suppression. They hope that since the Taisha had promised to be more open with the heroes, it will be easier for everyone going forward.
- The ending suggests that Yuna herself has a connection with Takashima Yuna, her namesake.