Let's go with Samidare! Naval Base Guide.

To guide the newly-arrived shipgirls around the base - this, too, is a important job of the initial members. (Drawn in 59 minutes). Because Samidare-chan is hard-working, cheerful and straight-forward, she's the best qualified for this mission.

She's anxious about Kawakaze-chan - maybe because even though she's the 7th ship, she also presents as the the Oneesan-ish 1st Ship of the New Shiratsuyu (Umikaze-class). The immediately preeceeding Onee-san, Samidare-chan, gives off an atmosphere like that of a youngest child, maybe.