After the "Love Ink" event, return to Worldly Desire Temple. If you haven't already, ring the giant bell, preferably in the morning before Bell is awake. At night, Monk Hoichi will be haunted by tiny spirits with bells for heads*. Talk to Bell and she asks for "Sweet Potato Wine" from Julie's bar and grill and gives you a coupon. This event ties into kissing Julie. Return with the Sweet Potato Wine and show it to Bell. She'll ask you to accompany her to the cave behind the waterfall where you'll watch her duel with Mr. Binchotan aka Charcoal. Return to the temple and she'll lament that the "Legendary Sword" is not enough. Return to the cave and defeat Charcoal to obtain a second sword and the resulting combination works to exorcise Monk Hoichi of his bell spirits. At this point, we find that Bell is not actually human but a fully developed "human bell." Talk to her out at the giant bell and she'll kiss you.
Note: * If this is not the case, you'll have to return to WDT again.