I'm under the impression that the guardian feature was started and then shelved? It's there but all it does is make them attack you.
The dev is kind of all over the place with where they add content. They have a tendency to start things and then drop them for something else that they think will be faster/easier/more interesting to work on.
I can agree, I suppose. Though he has followed through with completing the main questline so it's not like he isn't
too out of focus. But, yeah, there's still a good number of unimplemented things.
Like the school nurse (if there will be content, that is... I think she has a shoe box as well, holds the black high heels),
Some school shoebox content (moreso teacher/staff stuff, there's pictures already for teacher's/staff's in shoe battles... i.e. battle bgs in heels, feet with painted nails, dialogue [I think...? There
was some in an earlier version but was taken out and is yet to b re-implemented...]),
The giantess to the left of the school will apparantly get more content, as per all the options other than when battling her on her hands,
Planned stuff with Harity... more locations like the demon world...
I could list a lot of stuff that's been partially put in but not yet done. There's plenty of (mostly broken due to missing npc sprites) unfinished maps andd stuff, including ones like:
A fairy forest (not the same as futatsu forest),
an area named "mysterious island" that seems somewhat similar to the Tenjinsha Shrine (where the battle and scene replay stuff is),
a hole north of the West Darmidori Cave's warp point that insinuates the possibility of shrinking more,
a map for the school's pool area,
a couple of caves named "Koedame"; one being found in West Mistra Lake (with a lethal poison fog),
an area simply named "Little Girl's Room"... (err...),
Harity events related to the command option,
Visual appearances for different Harity clothing,
etc etc
There USED to be some others a few versions back too, like an entire town other than the mamono town (was one of the maps I meant when I said "broken due to missing NPC sprites")... even including some possibly spoilery stuff, like new boss names (though I'm not sure if those have been scrapped or not).
But there's only so much that can be done in a month, especially given that this is all being done on RPGMaker
XP, which first released
twenty years ago. So definitely giving credit that he is at least still pushing monthly updates (unlike quite a few other Patreon devs...

)