Sunsunsun is a Japanese light novelist best known as the creator of the popular romantic comedy series Alya Sometimes Hides Her Feelings in Russian. The author, whose name also appears as SunSunSun, began the series after a significant conceptual evolution. The initial idea was for an isekai fantasy story, but it was eventually reworked into two short stories before finally being published as a full-length light novel series.

The development of the series involved a fundamental rethinking of the core characters and their dynamics. An editor pointed out that in the original short story version, a beautiful girl openly showing affection toward a boy sitting next to her would naturally lead to a romantic relationship. To resolve this, Sunsunsun created a protagonist with low self-esteem who is passive about romance, while adjusting the heroine so that her Russian mutterings were framed as teasing rather than genuine confessions. This change ensured that neither character believed the other was being serious, preventing the relationship from progressing too quickly.

The choice of the Russian language for the story’s central gimmick was inspired by several factors. Sunsunsun explained that Russian was selected because many Japanese people recognize the sound of the language but cannot understand its meaning, with German, French, and Italian also being candidates. The final decision was influenced by the imagery of Russian cityscapes blanketed in snow and the perception of women as beautiful and pure, like the snow itself. The character of Yuki Suou, a fan favorite, was consciously designed by Sunsunsun as an otaku who has analyzed and actively embodies the ideal little sister character. Writing her dialogue and actions was described as incredibly fun because the author identifies as an otaku.

Sunsunsun has drawn from personal experiences when crafting the story. The episode where the heroine Alya makes a class presentation entirely on her own without asking for help was based on the author’s own experience in elementary school. Sunsunsun has also stated a personal difficulty with relying on others, which helps in understanding Alya’s feelings. The author was involved in the production of the anime adaptation of Alya Sometimes Hides Her Feelings in Russian within the scope typical for an original creator.

The Alya Sometimes Hides Her Feelings in Russian light novel series, illustrated by Momoco, debuted in 2021. The series achieved significant commercial success, surpassing five million copies in circulation and setting a new record for a romantic comedy within the 36-year history of the Sneaker Bunko imprint. A companion piece written by Sunsunsun includes a pseudo-isekai story where the characters from the series end up in a fantasy world, released as a Blu-ray bonus.