I'm not sure who the author of 'Step Up a Love Story' is. You might want to check the book itself, usually on the cover or the title page. Sometimes it can also be found in library catalogs or online book databases.
One possible theme could be passion. The passion for dance could fuel their love for each other. Another theme might be growth. As they progress in their dance skills, they also grow in their relationship.
The 'Step Up Love Story' could be about a romantic relationship that develops within the context of the 'Step Up' world. Maybe it's between two dancers who meet while chasing their dreams in the competitive dance scene, and their love blossoms as they support each other through various challenges and performances.
I'm not sure specifically who the main characters are in a 'Step Up Love Story' without more context. But it could be two lead dancers, perhaps a male and a female dancer who are the stars of the story.
One common theme is personal growth. In many of these anime, the characters grow as individuals while falling in love. For example, in 'Your Lie in April', Kousei overcomes his trauma related to music and grows as a person through his relationship with Kaori. Another theme is friendship. Often, the love story is intertwined with the friendships of the characters. In 'Clannad', Tomoya's relationships with his friends play an important role in his love story with Nagisa. Also, sacrifice is a theme. In some anime, characters are willing to sacrifice their own desires or goals for the sake of their loved ones.
Well, start by deciding on the setting and the time period of your love story. That'll give it a certain flavor. Next, focus on the chemistry between the main characters. Make it believable and compelling. Also, throw in some obstacles for them to overcome together to strengthen their bond.
Sure. 'Your Lie in April' is a great one. It's a story about a piano prodigy who has given up on music after his mother's death, but then meets a violinist girl who changes his life and they develop a deep and poignant love. Another is 'Clannad', which shows the development of love between the main character Tomoya and Nagisa through various school and family events. And 'Toradora!' also features a love story where two characters who seem like opposites at first gradually fall for each other while helping each other out in their respective love pursuits.
Since it's a love story in the 'Step Up' world, the main characters are likely to be young, energetic dancers. They could be a pair who meet by chance at a dance competition. One might be a street dancer trying to make it big, and the other could be from a more formal dance background. Their differences would create interesting dynamics in the love story.