To end up being with

Grammar: Time and Sequence » 〜ことになる

〜ことになる says that circumstances, rules, or other people bring about a result or decision. When the speaker makes the decision personally, use 〜ことにする instead.

Further Reading

Examples

Came to be studying with us with 〜ことになる

Learn the meaning and usage of the grammar 〜ことになる in Japanese, with examples from manga.
名探偵コナン » Volume 18 » Page 96

A new student joins Conan’s elementary school classroom. The teacher introduces her.

先生(せんせい):
今日(きょう)からみんなと勉強(べんきょう)する(こと)になった灰原(はいばら) (あい)さんです!」
“This is Ai Haibara. It came to be that she'll be studying with us starting today.”
「みんな仲良(なかよ)くしてあげてね!」
“Everyone be friendly with her!”

To end up betraying with 〜ことになる

Learn the meaning and usage of the grammar 〜ことになる in Japanese, with examples from manga.
レンタルおにいちゃん » Volume 3 » Page 120

Makoto explains to Misuzu that he’s been looking into various things since meeting Kanami, such as housing for orphans. However, he realizes what Kanami wishes for is to have her once-kind brother back to the way he used to be.

(まこと):
(おれ)()(はな)してしまったら」
“If I separate her from him...”
(かな)()ちゃんを(きず)つけて…… 裏切(うらぎ)ことになる
“...I'd be hurting Kanami... I'd end up betraying her.”

To end up cleaning for you with 〜ことになる

Learn the meaning and usage of the grammar 〜ことになる in Japanese, with examples from manga.
それでも歩は寄せてくる » Volume 2 » Page 134

Urushi and Ayumu give their makeshift clubroom a cleaning to welcome potential new members. Considering that Urushi was the only club member before he joined, Ayumu remarks how she alone had cleaned the room for his sake last year.

うるし:
「まぁ 結局(けっきょく)
“Well, in the end...”
「お(まえ)しか入部(にゅうぶ)してないからそういうことになるか」
“You were the only new member, so it ended up as you say, huh?”

Supplemental Examples

Try finding this grammar in the following examples: