The Holy Knight's Dark Road: Volume 2

After trekking through a labyrinth and coming back in one piece — with a new friend, to boot — Sain finally has time to actually study at Jenifa. In its hallowed chambers of learning, he applies himself to the acquisition of dark magic. A month later, he emerges... ...Still utterly worthless at dark magic. On top of that, his teachers have given up on him, and his classmates are calling him the Darkness Dork. Just when despair begins to set in, a chance encounter with an enigmatic girl brings him new hope. Her features are unmistakably those of a dark elf — known for their natural affinity for dark magic. He immediately asks to be her apprentice, only to be coldly rejected. This is Sain, though, and “giving up” just isn't in his vocabulary. Through his tireless — and arguably obnoxious — efforts, he chips away at her armor of indifference. Little does he know, though, that an upcoming school event will put their budding friendship to the ultimate test.

[From J-Novel Club]