cradle robbery and homosexuality
I'd like to start this section off with a quick review of Seishirou's and Subaru's ages throughout the two series.
Let's get this straight, now. When Seishirou made the bet with Subaru, Subaru was nine years old. Powerful onmyouji or not, he was only a child, and even if Seishirou hadn't erased Subaru's memory of the bet, I seriously doubt he would have understood much of it. At the time, he asks childish questions to Seishirou's calm explanation.
Seishirou: The cherry blossoms are so beautiful this time of year. Do you like cherry blossoms?
Seishirou: But don't you know? Underneath each cherry tree... is buried a corpse.
Subaru: A... a corpse?
Seishirou: Why do you think cherry blossoms bloom so beautifully each year? It's because of the corpse. You see, the flowers on cherry trees used to be white. White like snow. So why do you think cherry blossoms turn that pale crimson shade? It's because they drink the blood from the corpse underneath the tree.
Subaru: But... doesn't that hurt the person underneath the tree?
At the time, Subaru simply isn't old or mature enough to understand it; instead, he asks the piercing questions children are wont to. He has no understanding of the meaning behind the corpses underneath the tree. What really makes this scene so eerie in the last volume of Tokyo Babylon is the part Seishirou finally lets Subaru see again: the fact that they were having this conversation right beside a corpse. Subaru had fainted at the very sight of it, and Seishirou erased it from his notice to have a conversation with him about cherry blossoms and how if they should meet again, he would try to love him. All of this goes completely over Subaru's head and is erased from his memory.
So the question is: what the hell was Seishirou thinking?! He made a bet with a child that he would try to love him when they next met. That next meeting just happens to occur when Subaru is 16 and Seishirou is 25; Subaru has grown in years, but he's still a very naïve child who blushes every time Seishirou mentions anything along the lines of loving him. And bizarrely, no one seems to find this strange! Hokuto eagerly pushes Seishirou at Subaru as much as possible, more interested in supporting their relationship than anything else. In fact, she's more interested initially in the fact that they're heirs to opposing clans.
Hokuto: The Sumeragis operate in daylight, the Sakurazukas in shadows... and the leader of one and the heir to another are in love. How fabulous! How romantic! How melodramatic! How hard-boiled!
The fact that they're in opposing clans (though Hokuto and Subaru don't know that Seishirou is the Sakurazukamori) is less important to Subaru than the fact that they're both men.
Seishirou: I'm a man. And you, Subaru-kun, are a man too, but... all it means is that I fell in love, and the person I fell in love with also happened to be a man. But I suppose that's just an excuse to you. A man loving a man... that's just perverted, isn't it? Ha ha ha!
Hokuto: Well spoken, Sei-chan! That's right! No matter how much we try to pretty up the situation, Seishirou-chan, you're nothing more than a pervert! You crazy sicko, you, chasing after young boys!
Seishirou: Ha ha ha ha ha!
Hokuto: But that doesn't mean I'm going to tear you away from him! In fact, you have my full blessing!
Seishirou: Why, Hokuto-chan?
Hokuto: Because I find it amusing!
The fact that Subaru and Seishirou are both men comes up only occasionally in the series — in the "Call A" chapter, when they get their compatibility tested, the clerk behind the desk seems unconcerned that a grown man is checking his romantic compatibility with a high schooler and is only surprised by the fact that Subaru is male. In the "Box" chapter, the ghost in the karaoke box teases him about being in relationship with Seishirou. Still, aside from these instances, it doesn't come up.
Considering the various social issues CLAMP addresses in Tokyo Babylon, it seems odd that the relationship between Subaru and Seishirou is never questioned and is instead used as a running gag instead of a real relationship until late in the story. At that point, it becomes more about the revelation of the bet to Subaru than anything else, and any questions about their relationship ignored in light of the fact Seishirou was never honest about it.
I mention this because while obviously the fact that they're both men is not a bad thing by any means, it is strange to me that in a series that openly discusses things like rape, the elderly, and organ donation, and is explicity about a gay relationship, it never actually talks about the realities faced by gay people. CLAMP has portrayed a lot of different kinds of love in their works, and I do like the fact that they frequently depict same-sex couples, but it does seem weird to me that this never comes up in TB given the subject matter.
Ultimately, though, I think that Seishirou and Subaru's relationship — from the age difference to their gender — comes down to the fact that they're in a CLAMP manga, and not in-character decisions. While Tokyo Babylon is one of their earliest works, it's ended up being just one of many series to feature characters in same-sex relationships and/or with signficant age differences. To name a few other age difference pairings (since I'd be here all day naming same-sex CLAMP pairings):
- Kusanagi & Yuzuriha, X/1999 (she's 14, he's considerably older)
- Terada & Rika, Cardcaptor Sakura (he's a teacher, she's in elementary school)
- Fujitaka & Nadeshiko, Cardcaptor Sakura (she was 16 when she married her 27-year-old teacher)
If anything, the fact that Seishirou and Subaru's feelings are confirmed as mutual is unusual unto itself: in most CLAMP series, there's a lot of subtext, but characters don't often confirm their feelings for each other. (I'm looking at you, ×××Holic. And, you know, half their other works.) The fact that Subaru explicitly realizes that he's in love with Subaru, and that we eventually find out how Seishirou felt in return, cemented Seishirou and Subaru as an iconic CLAMP pairing, tragic as they are.