Granblue Fantasy's Mysterious 'Zundoko' April Fool's Teaser Ignites Fan Theories

A teaser for the popular game "Granblue Fantasy (GBF)" leading up to April Fool's Day on April 1, 2026, has become a hot topic on social media. Alongside a mysterious message stating, "Here comes that season again... With my new power, I'll plunge you all into the depths of terror...!", the phrase "first cry" (産声) was added, sparking various speculations among users.

Many X (formerly Twitter) users were puzzled by the phrase "depths of terror" (恐怖のズンドコ) posted by the official GBF account. The sound of "Zundoko" immediately led many to associate it with enka singer Kiyoshi Hikawa's hit song, "Zundoko-bushi." A flurry of posts expressing a mix of surprise and anticipation, such as "Is it a Kiyoshi Hikawa collaboration?" and "Only Kiyoshi comes to mind," has fueled imaginations about an unusual combination of a game and enka music.

Furthermore, the keyword "first cry" from the official teaser and the character image hinted at in the visual have given rise to the theory of a "baby transformation" event. Some users have made specific guesses like "Vyrn (a GBF character) learned magic to become a baby," and comments such as "What's the connection with pacifiers?" and "I want to see baby Vyrn" have also surfaced, indicating that many fans are anticipating a scenario where in-game characters turn into babies.

Additionally, some voices hoped for collaborations with rhythm games like "Taiko no Tatsujin" or "Groove Coaster," but most of these were developed from the "Zundoko = Kiyoshi Hikawa" association. This has heightened anticipation for an April Fool's project that is uniquely out-of-the-box.

Regarding the provocative phrase "depths of terror," users are excitedly anticipating the April 1st announcement, with comments like "I can't stop the excitement," "My heart can't keep up with the preparations," and "I'm going to be plunged into the Zundoko!" All eyes are on what kind of "Zundoko" GBF's annual surprise April Fool's event will deliver this year.

The context

Granblue Fantasy (GBF) is a hugely popular Japanese mobile role-playing game developed by Cygames. It is known for its extensive story, gacha mechanics, and frequent in-game events. GBF's April Fool's Day events are a highly anticipated tradition, celebrated for their elaborate, often humorous, and unexpected standalone mini-games or stories that deviate significantly from the main game's narrative. These events are a beloved part of the game's culture, known for surprising and delighting players with their creativity.

The term "Zundoko" (ズンドコ) is an onomatopoeic word in Japanese often associated with a rhythmic drumbeat or a cheerful, lively atmosphere. It is most famously linked to Kiyoshi Hikawa's iconic enka song, "Kiyoshi no Zundoko-bushi," which features the repetitive and catchy "Zun-zundoko-zundoko" chorus. The phrase "恐怖のズンドコに陥れる" (kyōfu no zundoko ni otoshiireru), which roughly translates to "to plunge into the depths of terror/zundoko," cleverly combines a seemingly serious or scary notion with a word that evokes a rhythmic, almost comical, feeling, leading to much amusement and speculation among Japanese speakers. Vyrn (ビィ) is a prominent and beloved dragon-like mascot character in Granblue Fantasy, making the idea of him transforming into a baby a particularly humorous and engaging prospect for fans.