Helena is a supporting character in the anime, identified as the cousin of a boy named Martti. Her primary narrative function is to serve as an antagonist to the protagonist, Katri. Helena's personality is defined by a distinct dislike for Katri, which manifests as a tendency to engage in acts of petty cruelty and mischief. Her behavior is not merely passive dislike but active antagonism, as she is specifically described as having a habit of playing tricks on the main character.

This adversarial nature is demonstrated through a notable act of sabotage, where Helena deliberately spilled beer on Katri's dress, an action intended to spoil the protagonist's clothing and cause distress. The story leverages her antagonistic relationship with Katri to create interpersonal conflict for the hardworking protagonist, highlighting the social challenges Katri faces despite her diligent and likable nature. There is no information available regarding Helena's background, motivations beyond her apparent jealousy or dislike, role in the wider plot, any character development or growth throughout the series, or any notable abilities.