Being at least somewhat cryptic is par for the course for Itomugi, so other than trying to translate as well as possible, I'm not going to try and spell out my whole reading.
A couple notes on the title, though: - Kaiko, spelled in katakana, is doing a lot of lifting as an at least triple pun, simultaneously meaning "silkworm", "reminiscence" and "termination of employment" depending on what kanji you use. Obviously that's impossible to replicate in English, but "threads" at least somewhat gestures in the direction of all three meanings if you squint. - Sairuiu really just means "teardrop rain", but specifically refers to rain that happens to fall during Tanabata, the festival that celebrates the brief reunion and reseparation of Hikoboshi and Orihime (whose name means "weaver princess", by the way).