It's possible that the black-haired guy has a determined expression. His jaw could be set, and his gaze intense, as if he's focused on something important above him. Maybe there's a hint of hope or excitement in his eyes as well.
He might have a curious or thoughtful expression. Maybe his eyes are wide and his brow slightly furrowed.
The black-haired guy could have a mixture of surprise and anticipation when looking up with the scarf. His mouth might be slightly open, indicating astonishment. Or, he could have a serene and dreamy look, lost in his thoughts.
Often, such an expression might involve tense muscles, furrowed eyebrows, and a tremble in the character's stance. It all depends on the context and style of the manga.
Maybe he had a bad day or got into a fight with someone.
It could be a friendship story where the two characters have different personalities but support each other.
They might be friends or have a romantic connection. It really depends on the context of the manga.
It could be Kurapika. He has black hair and is an important character in the manga.
One manga that fits this description could be 'Soul Eater'. It has various characters with different hair colors, including a blond guy and a black-haired one.
It could be that the guy has a thoughtful expression, maybe pondering the beauty or the mystery of the mountain. Or he might have a smile, indicating his enjoyment of the view.
The guy might have a concentrated look on his face, with his eyes fixed on the screen.
He could have a relaxed and peaceful expression, maybe enjoying the view. Or he might have a more intense gaze, as if he's thinking deeply about something in the sky.
There are a few like 'Neko no Kuroi Yoru' which has a black haired neko guy and is quite popular for its unique storyline and art style.