Timeline

Meeting:

Sakura Tenshi: Spike finds Sakura in her small form dangling in a tree. He rescues her from a cat and she follows him back to Bebop.

Question of Love:

Sleeping Desires, Tsuki Tenshi, Blind Confession, My Immortal, Ai Melody, & Little Tenshis: Both angel and cowboy seemed to have developed feelings for each other. But yet, they just don't know it yet.

Memory:

Sakura Lullaby: Kaze-san tries to help Sakura remember her past and realize her feelings for Spike.

Rescue:

Muse's Song & Mellow Rain: Sakura gets tricked into working in a strip club, but she gets away and Spike saves her.

Separation:

Heartbreak, Find Me, Wanderer, & Welcome Home: Spike disappears for a while, leaving Sakura feeling depressed.

Rescue Pt. 2:

Evanescence, The Long Night Pt. 1, The Long Night Pt. 2, Hostage, Blurry, Goth Jazz, Kuro Noose Pt. 1, & Kuro Noose Pt. 2: Sakura is kidnapped by Yuji because of her connections to Amadeus. Spike, T.J., Jet, and Shoji all come to her rescue.

Bonding:

Dream World: Sakura transports Spike to another realm after he rescues her.

Gifts:

Tenshi Wings: Sakura gets Spike a gift.

The Truth:

Fuji Tale, The Naked Truth, Purgatory, & Heaven and Hell: Spike and Sakura both learn the truth about their pasts.

Hot Love:

Sakura Virgin: Spike and Sakura first sleep together.

Rebirth:

Dark Wanderer: Spike is turned into a beggar this AU chapter, but Sakura helps him remember who he is.

Hot Love Pt. 2:

Virus: Spike and Sakura sleep together again.

Worry:

Aijin Pt. 1 and Aijin Pt. 2: Julia reappears and puts the couple's love to the test.