Sharing is caring

Chiku and Chako are identical twins who share similar preferences, leading to conflicts. Their friend Pinky helps them navigate these issues. During a circus visit, a magician's trick tests their friendship, but they resolve to share their bond generously, promising to remain united.

What promise do Chiku and Chako make to each other after rescuing Pinky?

What is the only problem that remains for Chiku, Chako, and Pinky?