終える

Etymology
→ (attributive) →  → (grammatical shift)  →  →

From verb wopu,   from.

The root verb was ambitransitive, with both transitive and intransitive senses conjugated using the pattern. Over time, the two senses differentiated as the intransitive evolved into modern, while the transitive evolved into modern.

Probably not related to superficially similar, considering the distinct lack of initial in ancient spellings.

Verb

 * 1) to end (something), to conclude (something), to finish (something), to quit (something)