Man, nobody does MILFs quite like the ones from the Tenchi Universe. It's too bad there isn't more hentai of them. There's plenty of good opportunities for femdom, etc. But more often than not, if they use the MILFs at all, they break character and make them subservient. Oh well, you take what you can get. I was really happy to see a rare good one with Airi (Tenchi's grandma!).
Unfortunately, this one had a second story interweaved with quite a bit of futa in it. Fortunately, it had very little to do with Airi's story. So I ended up cutting those bits out. As a result I'm calling this a rewrite (though honestly, it follows the original pretty closely -- except in places where the text was too blurry to properly translate). If you want the original, look for "(C64) [T2 UNIT & MAD MAC(c)(Franken N)] Kin Youbi no Tsumatachi".
Not really sure why, but I ended up decensoring this. It was quite a challenge, but I was happy to find it just kept getting more enjoyable as I went. Sensei had some incredible art hiding under the censorship. I only wish my skills were better so I could have done it more justice. For some reason, Sensei put his captions on p15 right over some good bits, so I moved them to the side. I'm including a clean version of the page as an omake at the end.
Seto-sama mentions Minaho and Kanemitsu having a similar experience. That seems to be a reference to "Carefree Minaho-san" by Saba Zarou, from "Ianryokou Toujitsu no Yoru" (already translated). Kind of fun to see artists back in the day referencing each other's works and building a common hentai-verse continuity.
If you're wondering, Seto-sama does indeed get her shot at Seina. I'm planning to translate that one at some point too. I haven't decided whether to do the whole thing or just Seto-sama's part yet.