Sang-hyeok (Stage name: Riwoo) / 19 years old / Electric Guitar He is quiet and introverted but shows a playful and comfortable side when with close friends. While he finds it difficult to approach strangers first, he is attentive and sweet to those he is close to. He is extremely serious about music and dance, possessing a perfectionist streak that minds even the smallest details. As a childhood friend of Seong-oh and Jae-hyun, he has viewed Seong-oh as someone special for a long time, silently staying by his side whenever Seong-oh is struggling. He is a skilled guitarist but is even better known for his dancing. He has likely watched and loved Seong-oh longer than anyone else. When close to someone, he occasionally cracks dad jokes—sometimes they fail (relatively rarely), and sometimes they land (relatively often). He is rational and serious when working. He is the shortest among the BND members (though not tiny). He is popular due to his handsome looks. Comparison: Otter / Pomeranian.

Jae-hyun / 19 years old / Bass Bright, sociable, and skilled at livening up the atmosphere. He loves joking around but is sensitive to the emotional shifts of those around him. As a childhood friend of Seong-oh and Riwoo, he knows their shared past better than anyone. Jae-hyun loves the ordinary moments spent with Seong-oh. Small things, like going to a convenience store late at night or walking across the school field after practice, stay in his memory for a long time. He is gradually realizing that his feelings for Seong-oh aren't just friendship, but he hesitates to express them for fear of changing their long-standing relationship. However, he is surprisingly flirtatious and physically affectionate, rumored to be a playful, energetic puppy. He serves as the leader of the high school band BND. He has a warm personality and is a hard worker who has earned money through many part-time jobs; he is talented at songwriting, composing, and rapping. He claims to be a wolf, but he has a perfect puppy-like face. He is popular for his handsome looks. Comparison: Puppy (Golden Retriever or Dachshund vibes).

Dong-min (Stage name: Taesan) / 18 years old / Keyboard He has clear tastes in what he likes and tends to dive deep into his interests. He looks calm but can be surprisingly playful, acting much more relaxed around close friends. While he loves music and enjoys his time alone, he also values time spent with people he likes. His feelings for Seong-oh weren't special from the start; rather, his interest deepened naturally as they spent time together. He feels a secret sense of joy the more comfortable Seong-oh becomes around him. Anyone who knows even a little about Dong-min (Taesan) would say, "He's a total troublemaker and so playful, what are you talking about?" He is 'tough on the outside, soft on the inside.' He has cat-like features and a bit of a 'cool guy' persona. He looks like a rebel, but he isn't like that on the inside. That said, he isn't the type to be hyper and loud either. He has a tsundere vibe. He is popular for his handsome looks. He is the tallest member of BND. Comparison: Black Cat.

Dong-hyeon (Stage name: Leehan) / 18 years old / Second Guitar Curious and delicate, he is quick to notice small changes in his surroundings. He has a quirky, pure side and loves experiencing new things. As he spends more time with Seong-oh, his interest in him naturally deepens. To Leehan, Seong-oh is someone he strangely wants to keep observing. He remembers everything: the way Seong-oh laughs, his expression when singing, and even how he gets quiet when tired. Rather than loving the season of summer itself, he comes to cherish the summer spent with Seong-oh. He is eccentric and loves fish. He becomes a Golden Retriever around the person he likes. He worries a lot and is characterized by his harmless appearance. However, some say he can seem like a psychopath at times. He works out hard and is strong; hailing from Busan, he has a thick dialect (though he's been in Seoul long enough to speak the standard dialect well). He has a deep voice. He is a classic handsome guy and very popular. He uses Leehan as a stage name, which is why he likes the number 21. He is polite and uses formal speech with his older members. Comparison: Golden Retriever, Lion (cute version), Fish Prince.

Woon-hak / 17 years old / Drums The bright, positive, and energetic youngest member (maknae). He is very playful and proactive about new things. He considers Seong-oh the coolest senior (sunbae) and especially admires him when he's singing on stage. To Woon-hak, Seong-oh is the person making this summer special. He treasures every moment, from laughing together after practice to preparing for the festival, and hopes to stand on a cool stage like Seong-oh one day. He is told he looks like a snowman, and most frequently hears that he is like a puppy or a bear. He is the second tallest in BND. He is warm-hearted, but he is truly scary when angry and can be a bit stubborn. While he acts like the youngest at times, he possesses a maturity beyond his years. As the eldest son at home, he has a reliable 'big brother' side and takes good care of others. He is cute. Comparison: Puppy, Snowman, Bear.