Date: 2019-09-19

事情がある

（誰か　に・には）事情がある means that someone “has something going on”, so to speak. This can mean various different things; maybe they have a nasty secret or a dark past, maybe they were abused as a child, maybe they just experienced an important milestone in character development or vowed to save someone’s life or something. Lots of possibilities.

In a way, it’s almost like 事情がある means that there’s complicating circumstances behind someone’s motivations, actions, interactions with other people, etc. Not just that they, like everyone else, do indeed have stuff going on, but rather that it’s of particular noteworthiness for some reason or another.

This nuance extends to various similar phrases, and 事情 can be modified. For example, 何らかの事情を持っている has the same nuance.

from 転生したら剣でした

「叔父上、私にはわかりません。彼女は何者なのでしょうかね？」

“Dearest uncle, I still do not understand. Just who is that girl?”

「私にもわかりませんよ。いえ、何者でもないのでしょうか？」

“I do not understand either. Nay, perhaps there’s nothing to understand?”

「どういうことです？」

“What do you mean by that?”

「我々は彼女が何かを隠していると思い込んでいました。しかし、そんな物、本当にあるんでしょうかね？」

“We have been operating under the assumption that she is hiding something from us. But of course, what if there is nothing to hide from us, after all?”

　無論、あの年齢で冒険者をしている以上、何らかの事情を持っていることは確かでしょう。多くの冒険者たちと同様にね。しかし、私たちが心配していたような陰謀や策略の類は存在しなかった。それが、情報を集めた末の結論です。

Of course, given that she’s living as an adventurer at such a young age, it’s clear that her circumstances must be unusual. As is quite common for adventurers. But there’s no intruige or deception of the sort that we were worried about. That is the conclusion that lay at the end of my investigation.

from Fairy Fencer F Advent Dark Force

【エフォール】「殺殺。殺殺殺殺、殺殺」

【果林（かりん）】「違う。札じゃない、必殺の殺だ。とエフォールは申しております」

【ファング】「はあ、なるほど。で、なんで殺殺言ってんだよ」

【ティアラ】「ファングさんいけませんわ。きっと深い事情がありますのよ」

(comprehension left to reader)

One should take note that the connotations behind 事情がある are not necessarily negative. For a similar, but unambiguously “negative” expression, see 訳あり, which focuses on defects (of objects) or baggage (of people). (These two expressions are not that similar, but can be unintuitive in the same way.)