Ah... I'm sorry. [He repeats that, though doesn't know what it is he is apologizing about - he really doesn't know her. Right? Except when he tries to remember if he's ever seen her around, he... can't.]
[...] Was it Seishirou-san who told you of it? The tree, I mean. [Because who else would it have been? This particular tree is only significant to the two of them.]