One alternative storyline could be a story of mentorship. Anko could take Naruto under her wing as a sort of apprentice in a special ninja technique. As they train, they build a strong respect for each other. Naruto's eagerness to learn and Anko's knowledge create a great dynamic. Their relationship could turn into a platonic love where they care for each other like family. For example, Anko could protect Naruto in a dangerous situation, and Naruto could show his gratitude by helping Anko with her personal problems.
A different storyline could be that they are partners in a mystery - solving adventure. They have to work together to uncover a conspiracy in the village. Along the way, they discover new things about each other. Naruto's optimism and Anko's street - smartness complement each other. Their relationship could develop into a romantic one in a very PG - 13 way. They might share a few tender moments while facing challenges together, like holding hands when they are in a tight spot or having a heartfelt conversation during a break in their investigation.