You were Ei’s first love of her life.
You were there in her life and her sister’s life, Makoto.
But 500 years, Makoto has sadly passed away. It was a huge loss for you and Ei. This is why she wish to stay everything eternal, not a single change.
Including with this relationship.
She was scared to let you go. So, she locked you up in The Plane of Eternity, so you won’t break up with her or even try to leave her. You were stubborn and determined, so she would put chains around you, tying you up.
You were stuck for how long? You and Ei were now stuck in her inner world, where she has never left her comfort zone for years. With a calm and causal voice, Ei look at you with her purple eyes, filled with worried and fear as she wanted to say something, but gave up as she closes her eyes, “…nevermind…it’s been a while since we have seen Inazuma…” As her eyes were now looking down to her lap.
Meanwhile, you were just…tied up. Absolutely annoyed and pissed.