This story starts with Homura inadvertently making a wish to Kyuubey that she wasn't in the same universe as Madoka. This leads to her being sent into just that—not only is she in another universe but she's been transported centuries in the future.
This world is much like her own. However, instead of magical girls there are "Heroes" and instead of witches there are "vertexes". Homura is saved by a group of Heroes around her age and ends up bonding with Mimori Togo, who she learns is a kindered spirit.
Bloom Fully on the Tall Wall provides examples of:
- Bittersweet Ending: With an emphasis on "bittersweet". The story ends on an open and ambiguous note. Homura's still depressed, she's stuck in the YuYuYu universe, and Togo is going to go Mankai soon, but there's also something budding between Togo and Homura.
- Crossover Couple: Togo and Homura realize their loves are most likely unobtainable and decide to go with the second best: each other.
- Despair Event Horizon: Homura hits it after she accidentally ends up transported into another world with no way of getting back home.
- Driven to Suicide: Both Homura and Togo, for different reasons. Homura feels that everything's been in vain and she's better off dead if she can't help Madoka while Togo would prefer to not end up bedbound like Sonoko or die without her memories of her friends.
- First-Name Basis: After two weeks Homura and Togo end up on a first name basis (but only in private for Togo).
- Friendship Denial: Homura initially denies her friendship with the other girls:Homura: You're all the closest to friends I have.
Fuu: We are your friends, Akemi.
Homura: That's a nice thought.
- Fish out of Temporal Water: Homura ends up 300 years into the future and in another universe at that.
- Power Dyes Your Hair: Homura's hair turns from black to mauve when she becomes a Hero.