"Thanks" question

[naitorii]

Hi, this may sound a little weird to ask, but I was watching anime, and a character said "ari" instead of "arigatou," is that a real thing you can do when speaking, or just a character quirk?

[LittleGaijin]

I never hear that, but after a quick search it turns out that it's an extremely informal way of saying "thank you" to a close friend... ("Arii" with a long "i" sound.) Ari (蟻) means "ant" though, so this sounds kind of silly for me to hear. It also sounds similar to the Japanese pronunciation of the name "Ally". That said, there might be some confusion if you ever use this, so I recommend not using it. If you want to be informal with friends どうも or サンキュー is much more often used. 

I'm wondering if this is part of a lesser known region's dialect, similar to how Kansai has their own way of saying "thank you". In that case, it could be a character quirk. If anyone knows, please speak up! I could be wrong.

[Jembru]

I second what Anna said. You should be very careful of using abbreviations and informal words like that, unless you really have a good relationship with the person with whom you're speaking, as you really could cause unnecessary offence. I'm sure you weren't even considering using it, but were just curious, but I'd hate you to use it to an online friend only to wonder why they went quiet and never spoke to you again.

Most people, truthfully, will forgive a learner for using inappropriate words, and will even find it funny. I've done it loads of times and it's just gotten a laugh. Now and then I'm gently warned though, like being told that frequently referring to a close mutual friend as '彼女' was kinda rude. No one fell out with me over that, because my friends appreciate that I am only learning, and as they all speak English, they know that we use pronouns a lot, so it just feels natural to do so. Still, I was warned to try to be more sensitive, and I guess some people who didn't know me so well, might be put off me if such slips happened too often.

They say a lot of things in anime that are probably best left out of speech (although some of my none native friends will use such things in skype chat from time to time, it's just for fun, because they know I wouldn't be offended.. at least.. I hope they're not trying to be mean ).

So, on that note, あばよ! ^^

[Bokusenou]

Hmm, I haven't heard it on it's own, but I've heard まいどあり a lot (short for or "Thanks, as always", what shopkeepers say to regulars). あり might be young people slang like あざす, etc.