She is not a tree, for a tree's trunk is sturdy and strong, and only its branches sway, only its leaves quiver, as the wind passes through.
She is not a bird, for a bird can spread its wings and follow the wind, feeling it pass beneath as it glides through the sky.
She is not a kite, for the fate of a kite is tied to that of the wind, and wherever the wind blows, the kite is forced to follow.
Instead, she is the grass, bending and twisting and twirling as the wind passes her by.
But the grass cannot move to catch up with the wind, so she must wait for it to come sweeping by her again so that she can feel its caress.
She loves everything about Okita Soji.
When he smiles at her, when he tells her something in confidence, when he greets her in the morning and tells her good night, she thinks to herself, I love this man.
It's something she can't say aloud, but she thinks he knows a little bit about it. Maybe not the full extent of her feelings, but he knows she feels love for him, knows she cares.
And that's enough. That's all he needs to know about her feelings.
Because when he speaks so earnestly about their goals, when he talks of Kondo-sensei and the others, when he shows that he's fully committed to all the things that are important to him, she thinks to herself, I will die for this man.
Not I want to but I will, because she knows that when the time comes she'll do anything to protect him, anything at all.
It is with a heavy heart that she visits him at his sister and brother-in-law's house in Edo. When she is finally left alone with him, she touches his hair, and he doesn't so much as move.
"We're retre—" she begins to say, but decides not to tell him of the Shinsengumi's plans. It's better that he gets as much rest as possible, that he doesn't worry about any of them.
But even she knows, as she whispers a soft goodbye and brushes her lips against his cheek, that no matter how much sleep he gets, he'll never improve. He is too weak, too pale, too ill to ever recover from this. Nothing she does will make him better again—nothing at all.
"Okita-sensei?" she murmurs, and a moment later, she tries, her voice hitching in her throat painfully, "Soji?"
But he doesn't answer, he can't. Tears begin to fall as she realizes she can't even give her life to save him. He will die here, in this room, in this very spot, and…
She will be left completely powerless as the wind passes her by one final time.
Well, the known facts about Okita Soji's death are bound to make it into the manga, though I'm not sure what all is going to be shown/explained. I think there are a lot of ways it can go, considering where Okita goes, and Sei's background in medicine, but this is one take I can see happening, regardless, where Sei says her final goodbyes before retreating to the Tohoku region with the rest of the Shinsengumi.
Thank you for reading! Feedback is definitely appreciated.