One-shot yaoi is not generally known for convincing motivations, by the way; it tends toward plot? What plot?

You might try Death Note, which is psychological suspense and which doesn't use any of the more stylized conventions that tend to trip up beginning manga readers. Ditto Blade of the Immortal, a gorgeously drawn manga about an immortal swordfighter and the teenage girl who drags him into her quest for revenge, with dialogue straight out of Quentin Tarantino.

Personally, I started with anime, which introduced me to and hooked me on some narrative and characterization conventions, and did not require me to follow page lay-out.