Isekaid 40ish Man Returns, Regressed as a Peerless 17-Year-Old

One night after meeting them, training begins earnestly.

Today, there was no tactical training by the instructor, only training under me.

In the morning, we had basic training and, in the afternoon, we had a mock battle.

In the mock battle, we were divided into three teams for a battle royal.

The teams were two teams composed of 10 Nordic soldiers each, and the last team is a team of me and Yui.

I did my best to hold back and support Yui moderately.

Yui should use this as an opportunity to train for a one-to-many battle.

As for the result, of course, an overwhelming victory for both Yui and me.

-0-

The first day of training went like that.

「What the heck is this training……」「It’s a hundred time tougher than usual」「That little girl, how the hell can she follow that training program?」

The soldiers had all collapsed and looked like a pile of corpses.

「Alright, Yui. Let’s start training.」

「Okay. The warm up is over.」

「「「Huh?」」」

The soldiers saw me and Yui leaving together shouted in unison.

-0-

「It’s been a while since Kazu and I trains with just the two of us.」

「I guess you could say that.」

Since Futaba joined us, the three of us are all training together.

「Ehehe, what are we going to do today?」

Yui smiled happily even though she must have been tired.

「We’ll train for underwater warfare at night. Underwater combat is very different. You’d better get used to it.」

「So that’s why you asked me to wear a swimsuit.」

Yui is currently wearing a swimsuit.

The swimsuit black tights combination is the ultimate maniac outfit.

「Once you get used to it, we’ll do it in your regular clothes. However, since it’s just the first day, we’ll focus on ease of movement.」

「It might be difficult if it’s not a bikini……」

Yui’s big breasts are strongly asserted from underneath her swimsuit.

I’d like to see her in a bikini but they might get off if she moves too hard.

As for me, I’m wearing a half pants and a t-shirt.

I can put a thin protective layer on the surface of my body so there’s no problem.

「Can you breath underwater?」

「I can’t.」

Right.

I cast a spell on Yui to allow her to breathe underwater.

I don’t really want to cast a spell on Yui that she can’t cast herself because she can’t respond in an emergency but in this case, I’ll cast the spell on her.

I also extended a thread of magic power to Yui so she could speak through her thoughts.

This is the same method we used in outer space.

-0-

Yui and I dived into the sea.

We are at the bottom of the ocean, where moonlight may or may not reach us.

The night is deeper here compared on land.

「Yui, do you have any underwater technique?」

「No but I can use gungnir.」

Underwater, Yui can’t use her speed, which is her strong point.

The purpose of this training is to make sure she can at least protect herself if there’s a similar situation.