The opening song is “Distance” as performed by Rie Murakawa while the ending song is “Salted Salmon, Salmon Roe, 893, and the Girl” by Yoshiki Nakajima.
The service has added the opening and closing songs to their channel which makes for a nice little bit of nostalgia.
The spring 2018 anime series Hinamatsuri is long done and gone at this point but Crunchyroll is doing some new promotion for it.
The work comes from the manga by Masao Ohtake that kicked off in 2010 and has thirteen volumes out.