Suga Koutarou (須賀 Suga) is a main character in the game Kirisame ga Furu Mori.
Suga is a young adolescent male, presumed to be around the age of 19 or 20, with raven-black hair and dark eyes. He is depicted to be wearing a black long-sleeved, sweater shirt and black jeans or dress-pants, much like a Gakuran, and a pair of formal shoes. He is a manager at a museum, and may often be seen with a sword. Later in the game, Shiori notices a light blue glow around the sword and concludes that Suga made the sword with night glowstone. He's also very tall.
Suga is generally silent throughout the whole game, although the reason for this is because he has no voice at all. He interacts with others entirely through memos; he lost his voice because he gave it to Kotori Obake in exchange for Shiori's extended freedom despite her promise with the Kotori Obake. He is quite serious and honest in his memos.
At the beginning of the game, he seems very aggressive towards Shiori in his attempts to get her to leave the museum, and was very stern when the governor attempted to purchase the property by telling him to leave. As the game proceeds, Suga reveals himself to be a sensitive person, and was labeled "a crybaby" by Shiori. He is shown to have a protective side, even going so far as to provide Shiori with means of protection through nightstone jewelry and offering his life to save her from harm. He is able to manufacture night glowstones, and is also able to construct necklaces.
Shiori and Suga have a very complicated relationship in the terms of balancing out whether they're incredibly good friends or possibly even more, though the ending allows the player to decide. Suga is shown to hold very passionate feelings towards Shiori, becoming forceful and attempting to remove her out of harm through getting her out of the museum, but when it's revealed Shiori is the owner of the mansion by legal rights, he opens up all of the rooms to her, and even follows her into the forest despite his past connecting with it.
When Shiori awakes from her flashbacks to her childhood, Suga is shown crying over her body, and even more so when she calls him by his childhood nickname. His personal feelings towards Shiori aren't entirely described, but are proven when, in multiple bad endings, he ventures out on a suicide mission against the Kotori Obake to buy time for Shiori to escape. In the true end, he calls her by her childhood nickname and says in a memo that 'there's a lot he'd like to talk about.'
Sakuma and Suga quite possibly might be at odds since she often hides out in the museum overnight and seems to be very dismissive of his constant annoyance with this. In Shiori's first encounter with Sakuma, Sakuma advises her to hide from the security guard, showing that she might be afraid of Suga in some sort of way. This may be because she was simply trespassing and didn't wish to be caught. She comments that Suga is "helplessly incomprehensible".
Officer Mochizuki and Suga seem to be on relatively good terms, as shown by the fact that Mochizuki adresses him as ''Suga-kun'', as opposed to Suga-san.