Yamada Yukina is Anna Yamada's father and Sanae Yamada's husband. He possesses a notably tall, muscular frame, standing significantly taller than his daughter. His long hair often falls across part of his face, lending an initially intimidating air to strangers.

He maintains a quiet, reserved personality, frequently communicating in a gruff, concise manner that can unintentionally sound threatening. Despite this exterior, he clearly demonstrates care and protectiveness towards Anna. Professionally, he works as a chef, a career that fueled Anna's own strong interest in food; he regularly prepared her favorite dishes to comfort her during childhood distress. His personal interests center on video gaming across multiple platforms. Ownership of consoles like PlayStation, Sega Dreamcast, Neo Geo, and Xbox is reflected in his clothing choices, and he reportedly favors playing supportive or healer roles in cooperative games.

Within his family, he shares a deeply affectionate relationship with his wife Sanae, including demonstrative gestures like carrying her during school events. Towards Anna, he embodies a traditionally protective paternal role, expressing reservations about her interactions with peers such as Ichikawa Kyoutarou, especially concerning extended visits to others' homes. His initial encounters with Ichikawa involved skepticism, heightened upon first seeing him near their apartment complex wearing Anna's clothing. Subsequent meetings during group activities like chocolate-making led to cautious observation. Gradually, he developed a rapport with Ichikawa, extending invitations for shared meals and exchanging gaming contact information to play titles like Monster Hunter together.

His character shows progression from wariness to conditional acceptance regarding Ichikawa's presence in Anna's life, balancing protective instincts with acknowledgment of their growing connection. His depiction is established within the primary series narrative.