|He's described as a cheerful and passionate character-- he even calls himself the Kingdom of Passion. In a majority of his appearances in canon, he has a smile to share with others. He's happiest when he's with his friends and to be honest, he considers almost everyone he meets to be a friend and when he's around them, he wants them to be happy. He gladly makes coffee for a stranger and he wants his group to win a costume contest for Halloween because he's extremely proud of them. If a friend needs help, Spain will jump to their aid whether it be teaching them how to make paper flowers or fighting to protect them. If someone is sad, he'll give them a cheer up charm to make them feel better.|
He announces that he'll protect his friends no matter what, even if it means putting himself in an unfortunate situation for their sake. For example, he completely neglects to take care of himself when he's protecting South Italy in the past. He invests in new clothes and projects for Romano but wears old, patchy clothes and drives himself into bankruptcy. He doesn't just do this once-- he does it multiple times. While he certainly gives his all to protect his friends, he does the same to defeat his enemies. He engages in a series of wars with Turkey and England when they meddle in his interests.
Obviously, he doesn't think about his actions all the way through and he comes off as a fool to others. After all, why keep fighting to protect South Italy or fight England when he's only making his own situation worse? It would be a lie to say he doesn't mind because it does stress him out to an extent. Luckily, he doesn't dwell on problems for too long, opting to think of nicer things. He also doesn't consider himself a fool; he does all of these things because he's just very passionate. While he doesn't appear to think very much about his actions, he tries to make sure that others don't know too much about his problems. When he's being attacked by England's pirates, he yells for no one to tell Romano. It also appears that Romano was kept oblivious to the full gravity of Spain's sacrifices and when confronted with the truth, Spain only shrugs it off and says he has problems managing money. Basically, he's foolish but he isn't stupid and he'd rather not worry.
Biography notes say he can't read situations and that he's so oblivious, he is easily taken advantage of. When he complains to France about his problems raising Romano, he's oblivious to France sneaking hands up his shirt. However, he really isn't as oblivious as some people might think. He actually has fairly good intuition such as when he's able to sense that he's being watched or when France is up to no good. But he is a rather hopeless when it comes to understanding people which is interesting considering how much he likes company. He carelessly makes comments about trading Romano for his brother and scolds him for being a brat when Romano was actually trying to help him. Spain does, however, realize after the fact that he's made a mistake and tries to resolve it. He also appears to be oblivious to the fact that Netherlands isn't very fond of him partially due to the fact that Spain thinks he's so popular.
Despite his cheerful personality, he isn't all smiles. As already mentioned, he's been plagued by money management problems in the past. In Hetalia terms, poor economies translate into colds. His economy becomes so terrible in the 1990s, he thinks he is going to die and he becomes incredibly dramatic. He begins to say his last wishes, declaring his desire to beat up England one last time. He ends up recovering though and acts as though nothing ever happened.
One could say that instead of worrying about the past, he focuses more on the moment… with some exceptions. He's definitely a character that can hold grudges. There's already the instance with still wanting to beat up England but there is also a moment in canon where America mentions that Spain is a jerk that kicks him in the back of the knees whenever they meet. During the Great Depression, Spain catches America's "cold" and at the meeting, cries out "Cuba!" and condemns America to Hell. This is all most likely a nod to the Spanish-American War in which America destroyed Spain's empire by taking away his last colonial possessions. Even then though, their current relationship doesn't appear to be too bad. Once you get past the teasing and the passive aggressiveness, Spain ultimately does invite America and England to participate in his April Fool's prank which consists of taking embarrassing photos and the like. He does, however, still find pleasure in their embarrassment over the entire event.
Already mentioned, he gets along with many people. England and America seem to be the two big exceptions because they beat him up in the past. Netherlands also beat him up in order to obtain independence but the two appear to get along in present times. They spend holidays together but it's also important to note that Belgium is with them so it's possible that Netherlands is only being "nice" for his sister. I say "nice" because their friendship seems reluctant on Netherlands' side while Spain casually spends time with him. Netherlands' victory over Spain does trigger a bit of a response from Spain though. In one strip, France mentions how funny it is for Austria to lose to a rising power (Prussia). Spain snips in to say that it isn't funny at all and it could happen to anyone.
Netherlands isn't the only example of one-sided relationships when it comes to Spain. In the past, he was also took advantage of Monaco and was rather unfair to her until their relationship became sour. Monaco appears closer to France than Spain. Spain is also described to have been cruel to his other territories while spoiling Italy. Despite this, Cuba mentions that he and Spain are getting along very well today.
Another significant relation of Spain's is Austria. Austria and Spain is one of the few examples of a canon relationship. In the past, they were married via the Habsburg Dynasty. During their union, Austria gave Spain control over South Italy. He was very reliable and loyal to Austria. Their personalities were very different; Austria often seemed fed up with Spain. Still, in the Austrian Succession War, Spain was sorry to fight him and in the present, Spain helps Austria make flowers. It might not have been a perfect match but they probably still got along while they were together.
Obviously, Spain hasn't and isn't always the best person. He holds grudges, he can be petty, and they say that when he drinks, he becomes sentimental and then scary to the point people should stay away from him. Just a note, the link isn't an example of him being drunk but it's just there to show you that he can, indeed, become a seemingly different person under certain circumstances. These traits combined lend to a mysterious aura of light and dark which was previously described as "another side" of Spain. Don't read too much into this though because in the end, he is really just a cheerful and simple country bumpkin that likes to drink wine, take siestas, eat, and take things at his own pace.