True. This is one of the few times I wouldn't mind there NOT be a possibility of sequel and have these two ride off into the sunset. Also, this artist really came thru with drawing a well-proportionate, voluptuous, beautiful female character. The thing is I've been noticing a trend in that in the stuff I've read lately.  (Edit: I can see Ashiomi Masato likes the chicks thick in his/her stories. Two thumbs up!)
Ah, so talking about the cats helped him build a closer relationship to her, eh? So I guess these onsen loving cats were being wingmen for the couple.
Great ending though. Ah, and once again the cats were being indirect wingmen and helping not only their relationship, but the ryokan itself, too.
And hey, he may as well make his extension...Indefinite, no? And then you can help run the place with the lovely girl who you should already be making your wife by now.
The obvious answer to the hey editor cliffhanger is 'Hey editor... I quit. Im gonna help run this place and fuck the owner until i die of an heart attack cumming h=in her 50 year for now.' Im a romantic.
A Horde Of Cats is Fine, Too ... plus they seemed to serve a dual purpose: (1) engaging a hookup between the Sexy Onee-san Matron (Umi-san) and the lone guest (Hiroyuki-san), and (2) attracting prospective visitors thereby rejuvenating the ryokan's business.
Unless they're both stone-deaf, OF COURSE the cook and the attendant "KNOW". Time and perhaps a sequel may yet confirm whether Hiroyuki's stay at the ryokan becomes *koff-koff* permanent (say-no-more, say-no-more).