How about "The Meek Inherit The Earth"? They could be the only large animal species left on their planet; so they eat plants and invertebrates like worms. There were aggressive species at one time, but recall how dinosaurs on Earth came to the end, but the ancestor of us humans survived: All the big animals died in the asteroid strike and subsequent nuclear winter. Our ancestor (and long before anything like primates existed) was most likely nocturnal and living in burrows.
So, say some similar but worse natural disaster befalls your planet; and the only surviving animals were prey, not very aggressive in the first place, highly social, vegetarians. Without predators, the smarter among them are selected as leaders because of their ability to find food and shelter in the post-disaster hell scape.
Say they have a natural deference to such leaders, and (as we already see in wolf packs IRL) only the 'best' are allowed to mate; the rest of the pack jointly cares for the young. (In wolves, the alpha male and alpha female are chosen by aggression, but presume in this non-aggressive species, all that mattered was the intellectual ability to solve survival problems).
High intelligence develops; the evolutionary pressure for millions of years is just making a living in scorched rubble; but their species is so social that all of them see themselves as subservient to the group, even the leaders are not self-centered or focused on personal gain or reproduction, reproduction is something they do if and when their group is shrinking. But their "love" is always for the group; not for each other.
Although the stories for this species might be boring (for us humans) because everybody is a selfless altruist, conflict is possible if they meet aliens.
Their love is for their own species, and the conundrum of what to do when confronted with a violent enemy is something to write about. How do they see such violence? Perhaps like a poisonous plant or moss on their own planet, something to be eradicated, so it stops harming them and opens up land to be cultivated, to feed more of them...
Heck, they could see entire planets in this way: There is new farmland down there, covered in what they see as dangerous and poisonous insects, spiders or plants, (but are actually humans) that must be eradicated so they can replant and colonize! They aren't "aggressive", they evolved without any other animals for a few hundred million years and are just incapable of seeing anything that is not their own species as anything but the equivalent of our plants, worms, insects, spiders, etc.