Causes and dependence with 因
因 means “the basis for something to come into being” or “a foundation”.
Etymology
This kanji is an pictographic character comprised of 囗 as an enclosure and 大 as a person, such as a person lying on a mat.
Causes
原因 (Cause)
原因 refers to the underlying factor or reason that leads to a particular result or state. It is primarily used to explain “why” negative events such as problems, accidents, or failures occurred.
It combines 原 (origin) with 因 (cause) to show the originating cause.

After cheerleading practice, Sakura overhears her friends talking about incidents at the school pool, where Sakura and Chiharu were among those mysteriously pulled underwater.
- 千春
( : - 「きょう また プールで足
( 引( っぱられておぼれそうになったんだって」- “I heard that today, someone got dragged under the water at the pool and almost drowned again.”
- 奈緒子
( : - 「こわいねーーー」
- “That's scary!”
- 千春
( : - 「先生
( が原因( がわからないならプール閉鎖( するしかないっていってたよ」- “The teacher said that if they can't figure out the cause, they'll have no choice but to close the pool.”
- Literal: “The teacher said that if the cause isn't known, there's no choice but to close the pool.”
- “The teacher said that if they can't figure out the cause, they'll have no choice but to close the pool.”
死因 (Cause of death)
死因
It combines 死 (death) with 因 (cause) to show the cause behind a death.

Inspector Megure suggests the murder suspect committed suicide by drowning himself. The medical examiner disagrees.
- 監察医
( : - 「ですが死因
( は溺死( ではありません…」- “However, drowning wasn't the cause of death...”
- 目暮
( : - 「え?」
- “What?”
- 監察医
( : - 「解剖
( してみないと断定( できませんが… おそらく毒物( を飲( んだあと池( に入( ったものと…」- “I can't say for certain without an autopsy... but it's likely he took poison and then entered the pond...”
- Literal: “I can't determine it unless we try an autopsy... but perhaps he entered the pond after drinking poison...”
- “I can't say for certain without an autopsy... but it's likely he took poison and then entered the pond...”