Like most characters outside Kiri, Itachi's name is written with katakana rather than kanji for weasel 鼬. But in Japanese, tiger sharks are called weasel sharks - itachizame (鼬鮫), with the first kanji from the meaning of Itachi's name and the second from Kisame's. While they're from a different family, another kind of tiger shark comes up in their meeting, as the description of shark pups devouring each other in the womb matches the otherwise docile sand tiger sharks.
And then there's Kisame's given name. While the kanji used are for demon shark, using different kanji, 樹雨 'kisame' is a noun. It's used for when fog settles around tree leaves and falls like rain. So a Mist Ninja finding their place alongside Leaf Ninja through the Rain Village/Akatsuki is literally summed up in his name
While being the only team to share ring placement and nail polish colour, the kanji on them, Vermilion and South, also match. Many of the Akatsuki rings are connected to heavenly beings in some way, but Itachi's, Konan's, and Deidara's are part of a set of Four Auspicious beasts - The Vermilion Bird, the White Tiger, and the Azure Dragon. They're all linked to different elements/weather/etc, tying the two of them together, as the Vermilion Bird is the deity of the south. Each of the symbols also has different phases of the moon connected to them, called mansions; one of them for the Vermilion Bird is 鬼, the first kanji in Kisame's name. And the main occurrence of the south kanji in the series is the Uchiha's Naka Shrine and Naka River; 'The Shrine/River of Southern Joy'. Itachi's Mangekyo Sharingan activates at the river, the tablet describing Infinite Tsukuyomi is in the shrine, and they meet by a seaside shrine.
Oookay, first up, a silly little experiment trying to draw in ZUN’s style (I think for the first time ever? I never did back in the olden deviantart days almost a decade ago now, wow) kicked off by me noticing that there aren’t any Touhou characters based off of kamaitachi (type of youkai, lit. “sickle weasel”, has sickles for claws and flies around in strong winds causing cuts in your skin which are actually just it cracking open from it being dry and cold), but the pokémon Sneasel is! So, Touhou Sneasel gijinka. I’m not 100% happy with the design, I think I could’ve been more creative with the head area for example, but I figure I’ll just fix it up if I ever draw her in my normal style. Didn’t put too much thought into my character; I’m sewing and I’m using Ephy as a pincushion (I did used to do this; his middle section is full of beans) and my title is just a pun on my name.
Speaking of names though, hoo boy I spent like two days crawling through Jisho for these (eternal disclaimer: I’m not a native or even particularly fluent speaker and don’t have a perfect grasp on what does/doesn’t sound natural in certain contexts; my name is deliberately silly though). Hitsuki’s last name was pretty easy, I just put together the kanji for “wind” (風) and “weasel” (鼬), using pronunciations that together sound like the word for winter, variable amount of extra u’s notwithstanding. For her first name I ended up using the first syllable of the kun’yomi for several kanji, which I think is a thing people do for girls’ names irl? So the first kanji is “conceal” (潜), part of the word “sneak in” that bulbapedia says is part of the etymology for Sneasel’s Japanese name, Nyula/Nyuura, and then it’s “claws” (爪) and “fangs” (牙), and then after I decided this I found out that Sneasel’s old pokédex entries talk about them hiding their claws lol. Also less of an influence, but Hitsuki sound like the word for “starting fires”, which is used metaphorically in at least one compound word to mean troublemaking, which seems appropriate. I couldn’t resist alliterating the title, though I super didn’t want to bother writing out titles in Japanese or figuring out abilities so I didn’t.
As for me, I found some fairly uncommon kanji I could stick together to sound like “Rendoufu”, which is close enough, and they mean “tangle/fasten with thread” (縺), “stab/prick” (撞), and “fabric” (布). And then Kit (the word kitto means “for sure” but also just the English word kit). So I named myself Sewing Kit in the funniest possible way I could find (which is why my names aren’t in Western name order; idk where the initial should technically go but eh), and then threw “picture/drawing” (絵) on the end for good measure. Ok that’s everything I think