Who cares if it's a little predictable and is seen as cliche now? Hiro going up to spend the rest of his life with Lucia, surrendering the right to return to Lunar in the process, melted your heartstrings. Especially Lucia's reaction. Admit it.
Lucia's theme, the song that plays during that moment, is also very heartwarming.
In Eternal Blue, after Lemina is thwarted by the rest of the party in her attempt to charge the inhabitants of the snowbound village for getting rid of the monster, if you talk to the sick young child in the village, you'll see the following dialogue (except in the remake), which doesn't quite square with her established personality:
Lemina: Somehow, that "thank you" makes it all worthwhile.
Hiro and company giving Ghaleon a Patrick Stewart Speech, declaring that they'll beat Zophar with the "power of humanity".
Lemina's speech when she confronts Borgan in Neo-Vane.
"We must hold together!" - Note the distinct difference in Lucia's behavior before and after the party goes to fight the monster creating the snowstorm. After Lucia rejoins the party, she gains access to her Healing magic. If the entire party has taken damage, she has a priority system which tells her AI who to target first. One guess as to who is at the top of the list, and here is a hint - his name starts with "Hiro".