He might be sweaty and a bit out of breath from the climb.
Perhaps he is wearing typical Parisian fashion, like a stylish beret, a long coat, and nice shoes. His face could be determined as he focuses on reaching the fourth floor. He may also have a small bag with him, either a fashionable backpack or a leather satchel, which contains his personal items.
Well, he could be a young, fit man with a confident stride despite the four - story climb. His hair might be tousled from the effort. He could be wearing a scarf casually draped around his neck, which is a common accessory in Paris. His eyes might be bright with anticipation or purpose, and his overall appearance would likely blend in with the Parisian aesthetic, yet still have a unique charm that sets him apart as a 'new man'.
Maybe he is trying to get a better view of Paris from a higher place.
It depends on his fitness level. If he is very fit, it might take him around 10 - 15 minutes.
It could be that he is in an emergency situation. For example, there was a fire in the building and the stairs were blocked, so he had no choice but to climb the outside of the building. And he might have some basic climbing knowledge and enough courage to attempt this dangerous climb of 15 stories.
If he was climbing for a legitimate reason, like a rescue operation or if he had prior permission from the building owner, then it could be legal. But just randomly climbing 15 stories of a building in Philadelphia without any authorization is likely against the law.
It could be that the elevators are out of order and he's in a hurry to get out of the building, so he chooses to climb down 15 stories. There might be an important meeting or appointment he doesn't want to be late for. Also, perhaps he just wants some adventure or a physical challenge, although climbing down 15 stories is quite a risky adventure. He might be a thrill - seeker who likes to do extreme things.
He could be doing it for a bet. Perhaps he wagered with his friends that he could climb that many stories.
It could be a dare or a part of some extreme fitness challenge he set for himself. Some people like to push their physical limits in unique ways, and climbing 15 stories is no easy feat. It might be his way of proving his strength and endurance to himself or others.
An adventurous person might do it. They love to take risks and seek challenges, and climbing 15 stories is definitely a huge challenge.
He could be a mysterious stranger that Sakura met by chance. Maybe at a coffee shop or during a trip.
People interested in stories about masculinity and the challenges men face might be interested. Also, those who like reading about different forms of struggle, whether it's a fight for justice or a personal fight within oneself.