miss kobayashi's dragon maid tohru

He reached into his inner self, feeling his energy circulating through his system, and began upping the intensity. By increasing one’s energy flow like this, a magic user could gather their strength for a spell quicker and easier. The problem was that doing it wasted energy and resulted in fatigue. Before a race, a sprinter might hop up and down or jog in place to get their blood flowing faster, allowing them to reach their peak earlier, but if they did it too much, they might find themselves out of breath when they needed it.

“Unnnnh!” I moaned happily. It went in much easier than it had the first time, after several days of near-constant practice, but it was still really a stretch for my poor, tiny, tight little teenage pussy! I tried to maintain eye contact with Mom as it was happening, but I just couldn't help them fluttering closed. I pushed myself back a bit, getting myself to the height I knew Daddy liked best and making my cute little ass really pop for him, then leaned down to rest my head between Mom's big, soft D-cup titties.“Babe?” Mom asked tremulously, her voice weak and thready.

idk if you've played chaos;head (or watched it, I never saw it so idk if it's in the anime) but it's set in the same world as steins;gate (which I've watched but never played) and things the eyes see but the brain doesn't process are a literal plot point, you could almost certainly make a fairly lore accurate manip with that if you like this world.