TV-Series
Description
Enta Jinnai is a 14-year-old middle school student sporting orange-tinged hair, lime green eyes, and round thin-framed glasses. His typical outfit consists of a beige sweater with a red triangular neck stripe and straight red line at the bottom, a white shirt, blue trousers rolled up at the ends, and orange shoes. Upon transforming into a kappa, his skin turns light green with a paler green belly; he retains his glasses but gains a large yellow bill, a sara (plate) atop his head, an orange neckerchief, and a wavy-patterned kappa shell.

As Kazuki Yasaka's childhood friend, Enta once formed a soccer "golden duo" with him and yearns deeply to revive this partnership after Kazuki quits the sport. He harbors a secret romantic crush on Kazuki, fueling intense jealousy toward transfer student and delinquent Toi Kuji, who becomes involved with Kazuki. This jealousy sometimes drives Enta to impulsive or immoral actions, like fiercely guarding a soccer field he considers his own. Despite these moments, he shows strong loyalty and protectiveness: he helps Kazuki maintain the secret of cross-dressing as idol Sara Azuma to communicate with his brother Haruka, and assists in caring for wheelchair-using Haruka. Enta initially distrusts Toi due to his criminal activities, viewing him as a threat to his bond with Kazuki.

Following an encounter with the kappa prince Keppi, Enta and his companions gain the ability to transform into kappas. To revert to human form, they must extract shirikodamas (soul-containing organs) from kappa zombies by performing the "Sarazanmai" ritual, demanding emotional and physical connection among all three. Each Sarazanmai forces one boy's secret into the open, creating tension. Enta struggles with this required connection, especially as Kazuki grows closer to Toi. This struggle peaks when Enta confronts Kazuki after he gives his Dish of Hope (a wish-granting item earned during missions) to Toi instead of using it for Haruka. Kazuki's declaration that he "hates Haruka" during this confrontation further strains their relationship.

Enta stands 158 cm tall and weighs 45 kg. His personal preferences include a fondness for croquettes and the color yellow, while he dislikes raw egg. Appearing in all eleven episodes, his character development centers on balancing his intense feelings for Kazuki with the necessity of cooperating with Toi to achieve their goals, navigating jealousy, loyalty, and the complexities of adolescence.