Maybe a mysterious stranger who comes into Beckett's life by chance. For example, a writer who is doing research in the same library as Beckett. They strike up a conversation about books, and there is an instant connection that leads to a deeper relationship.
One possible plot could be that Beckett, after going through a period of self - discovery and growth, meets someone new in an unexpected place, like at an art gallery. They start as friends, sharing their love for art and literature, and gradually fall in love. Beckett decides to remarry because this new person makes him feel alive and understood in a way he hasn't felt before.
Another option could be a co - worker. He sees Riley going through the pregnancy and is drawn to her strength and vulnerability. He starts to spend more time with her, bringing her food when she has morning sickness and helping her with her work tasks. This closeness could develop into a love interest.
Perhaps a Saiyan female. Since Broly is a Saiyan, it would make sense for him to be paired with someone from his own race. They could bond over their Saiyan heritage and power.
There's a possibility that it's an old acquaintance from her school or work. They might have had some interactions in the past, but nothing romantic. However, after Sakura's experience of falling out of love, she starts to re - evaluate this person. This acquaintance could have changed over time and become someone more appealing to Sakura, perhaps more confident or more empathetic, which makes her consider him as a potential new love interest.
A former acquaintance of Beckett who has turned to a life of crime could be an antagonist. They might have some old grudge against Beckett, like Beckett once reported them for something minor but it led to them having a really hard time, so now they want revenge by holding Beckett hostage.
A new Bakugan trainer in town could be his love interest. She's fresh, full of energy and her unique Bakugan battling style catches Ace's eye.
It could be one of his female classmates. In the Clannad world, there are many female characters around Sunohara in school. Maybe a girl who is initially annoyed by his boisterous behavior but later comes to see his good side.
Maybe a new character, like a mysterious meister who arrives in Death City. She could have unique powers and a personality that attracts Death the Kid. Since Kid is so into symmetry, she might have some symmetrical features or abilities that draw his attention at first, but then her inner self is what really makes him fall for her.
Perhaps a scientist who is working on a related project. She would be attracted to Chase's intelligence and his bionic abilities. And Chase would be drawn to her knowledge and her determination in the scientific field. They would start collaborating on projects and slowly fall in love.
Maybe Rukia could be a potential love interest. She has a strong connection to the world that Urahara is a part of. They both have a deep understanding of the Soul Society and its workings, which could form the basis of a romantic relationship.