Their relationship could start slowly. At first, they might just be colleagues or friends. Kyouma might be too focused on his time - travel experiments to notice Luka's growing feelings for him. But as they face more and more dangerous situations together, they would start to rely on each other more. This would lead to a deeper emotional connection.
Perhaps a plotline where Luka has a premonition about something bad happening to Kyouma in a different world line. She then tries to use her unique abilities to prevent it. They could end up in a series of misadventures as they try to find the right way to avoid the predicted disaster. This would involve a lot of time - leaping and trying to outwit the forces that seem to be against them.
It's a tough call. Tsuna has shown great potential and a never-give-up attitude, but Xanxus is a formidable opponent. The winner could be decided by a sudden twist or a hidden power that either of them possesses. We'll just have to wait and see how the manga unfolds.
Well, Koikano and Aikano share a focus on emotional connections, but the settings and plot developments are distinct. Koikano might have a more complex plot, while Aikano could focus more on character growth.