Yuina starts working at Kissuiso to gain some experience, and inadvertently leads Ohana to logbooks written when her mother Satsuki was 16.
The logbooks highlight the problems between Satsuki and her mother Sui , and trigger the parallel flashback story.
I think this story gives us our first look at Ohana’s father, and at Satsuki’s almost inadvertent romance with/by him . I’m going to skate lightly over the rest so as to keep this to “minor spoilers” level.
In the present day there are a series of problems besetting Kissuiso and the staff, and these problems are neatly structured to throw a light on all of the major female characters – Minko, Nako, Tomoe, and Sui all get some nice moments, and we also see a lot more of Nako’s much younger sister Mana.
The interwoven stories work surprisingly well, both in terms of helping Ohana understand her mother and in terms of Ohana using that understanding to help Nako find a missing Mana.
Home Sweet Home is quite a short movie at 66 minutes. In essence neither story is given much more length than a TV episode plus the framing scenes. I grant that there is probably scope to have done more with Satsuki’s story, but Ohana’s story would have felt padded if it was any longer.
Balancing the two felt right, and I think adds to the emotional resonance of the film. I enjoyed Home Sweet Home, and it certainly had a few quite effective tear jerker moments.
I really wanted the Hanasaku Iroha film  to be Ohana’s return to Kissuiso as an adult.
Since I can’t have that, I’ll take what I can get and Home Sweet Home is definitely worth a look for fans of the TV series. To tempt you, here’s one of the commercials: