[romaji and translation] Days

[masa]

I don't think so.

(4) I've known for a long time that you have someone precious
Because it's clear from your smile

This stanza shows that she is rather calm, even knowing that. But the stanza (5) shows she is not calm at all in some nights. So the conjunction must be "though".

And I change "it" to "this", taking your advice. Thank you.