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.
One possible theme could be growth. As the characters take the next step in their love, they grow individually and as a couple.
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.
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 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.
Common themes include perseverance. The stepmom has to keep trying to love and be part of the family, even when faced with rejection or difficult situations. Understanding is also key. She needs to understand the kids' feelings and the family dynamics. Love that transcends differences is another theme. The stepmom may come from a different background than the family, but she finds a way to love them all the same. And finally, the theme of creating a new family identity. She helps to shape a new family unit where everyone feels included and loved.
One common theme is acceptance. The step mom has to accept the new family situation and the children, and vice versa.
One possible theme could be acceptance. Skylar Vox might have to accept her new step - sister into her life and family. Another theme could be jealousy. There could be moments where either Skylar or her step - sister feel jealous of the attention the other gets.
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.
A third theme might be the pursuit of dreams. If one or both of the lovers had big dreams, like traveling the world or becoming an artist, their love would be intertwined with their individual pursuits. They might have to choose between love and their dreams or find a way to make both work in the context of their relationship.
One possible theme could be sacrifice. In 1941, during the war, lovers might have to sacrifice their time together, or one might sacrifice their safety for the other. Another theme could be hope. Despite the dark times of war, their love could be a source of hope for a better future.