© 2026

Story

Rin, a 17-year-old high school girl, wandered into an Isekai where the sky is always pink in color. Ruka, a 14-year-old girl who speaks a little Japanese, and a couple of other girls teach her Juliamo, the lingua franca of the world. Will Rin be able to exchange KOTONOHA with them with a smile?

• Juliamo is constructed based on Esperanto, a real language in our world.

About the Isekai Rin has wandered into

[Difference between the world where Rin is from]

• While geographically similar, some buildings, facilities, and roads are completely different.
• The language is the most critical difference; the people do not speak Rin's Japanese.

[The people called Vizitanto]

• Many people other than Rin have wandered into this world from other ones; they are called Vizitantos.

[The language Juliamo]

• In the past when there was a massive influx of Vizitantos, a certain language was common among them. Juliamo is constructed based on that tongue, and is used as the first language in certain regions.
• The alphabet consists of 28 characters, highly similar but pertaining some differences to the 26-character Latin alphabet.

[The sky that doesn't change in color]

• The sky is always pink in color; are there no sunset?
• The lack of visual difference between day and night has led to a general preference towards 24-hour clocks.

Characters

• TAKATOO Rin (17, Female) Voiced by: Juri Nagatsuma

"Do I... actually happen to be gifted in languages?"

A high school girl who wandered in to an Isekai. Specializes in positive thinking! While not the greatest fan of learning, she tries to learn Juliamo in order to communicate with Ruka.

• Ruka (14, Female) Voiced by: Shu Uchida

"I like... Rin!"

A middle school girl who serves as Rin's caretaker (?). Though not fluent, She tries to speak with Rin in Japanese after she wandered into her world. She seems to be living by herself while still being young, and her parents are nowhere to be seen; there seems to be more behind this.

• Rei (??, Female) Voiced by: Sarah Emi Bridcutt

「Ĉu vi jam povas paroli la lingvon Juliamo?」

A woman who works at the Vizitanto Service Bureau, where Ruka took Rin to. Normally she serves a librarian for the library in the adjacent building.

• Kanako (15, Female) Voiced by: Eriko Yamana

「Fek! Fermu la buŝon!」

A girl who seems to be a friend (?) of Ruka. She seems to have some thoughts on Rin, but is harsh on others and rough in speech.

• Nora (??, Female) Voiced by: Anzai Yukari

「…………」

A blue-eyed blonde girl, low in height and childlike in appearance, who suddenly appeared in front of Rin and Ruka. The Isekai language she speaks seems to be different from that of other girls, with a bit of an "accent," one would say.

The meaning of the title

KOTONOHA = language Lernado = lernado (EO) Adding the suffix -ad- and noun suffix -o to the Esperanto world lerni (to learn) yields lernado (learning).

• -ad- adds the meaning of continued action. "To continue learning" = "Learning"

The meaning of the brand

SukeraSparo. A compound from Espranto words sukera (sugar) and sparo (sea bream), signifying the store "Taiyaki shop" in the novel.

Product

Character design by: Chisato Naruse Planning/Scenario by: J-MENT Language supervision by: HUZIMAKI Ken'iti Hotta Hirohiko Japana Esperanto-Instituto Director: J-MENT Producer: Shuichi Koga Developer: SukeraSparo