Future Daughter Musemon

"I'm so hungry..."
The protagonist, Naoto Nabeshima, is a third-year university student. And right now he's in the crucial crunch period of exam prep.
"But I still have to memorize about one more page."
Naoto, tears in his eyes, buries himself in his notes, marking words and sentences that seem important with a highlighter.
"Last page..." Just then—
Clatter, clatter clatter!!
"Mm-hm~ Heave-ho... just a little more and I'll be out~"
The voice is coming from the desk drawer! Could this be a hallucination from studying too much!? No, surely he hasn't studied so much that it's come to this!!
"Da—ddy—!!"
The drawer suddenly bursts open with a "bang." Naoto takes the full brunt of this "drawer impact" to the stomach and falls flat on his back, just like a kid playing on a chair in elementary school.
"Heave-ho. ...Phew, I'm finally out... So this is the early 21st century..."
"Um... it should be right here. Where on earth is it?"
A girl with a ponytail stands on the floor, spinning around and scanning the room. Whose kid is this? And why did she come out of the drawer, out of the drawer...
"Daddy, I found you!! I'm Aoi. Nabeshima Aoi."
"I came from the future to see you, Daddy. I'm your daughter."
Creak, creak...
Right after that, two more girls emerge from the closet and from under the tatami mats.
"Da~ddy!! Huh, where's Daddy?"
"Oh my? Father... where might you be?"
Ut·ter·cha·os.
Naoto yells "How should I know!" and flees the room, dashing to the bathroom.
Splash—
"...Ah."
"Da~ddy... Young Daddy, nice to meet you..."
"Not a—gain—!!"
Suddenly, from the future! Four daughters come barging in. Setting aside whether it's true or not, just as Naoto thinks, "I'm going to have four daughters in the future?" he realizes the four don't know each other at all. Not only are they not sisters, but each insists she is Nabeshima Naoto's one and only daughter.
What on earth is going on???
Are three of them lying? Or will Naoto sink so low in the future that he has three illegitimate daughters!? Or else... Plunged into confusion far beyond "totally baffled"—more like "baffled ten times over"—Naoto finds himself tangled up in one bizarre situation after another, and so his life living under one roof with four daughters begins, vaguely and haphazardly... (To be continued)