The pairing is sometimes referred to as Giripan, a portmanteau of the first few syllables of Greece's name in Japanese and the last syllable of Japan's name. This pairing is also called ねこんび (Nekonbi), Cat Combo, in the Japanese fandom.
Greece and Japan and the Cat Relation
At the beginning of the strip, Greece explained that he had been good friends with Japan for a long time and that he felt grateful to Japan for helping him with his trade deficits and selling him inexpensive yet durable cars from his country.
Greece also enjoyed visiting Japan to see more of his culture, such as samurai and shrines, and Japan was shown explaining to him how to invoke the gods at one of his shrines. Greece asked him if it was okay for him to wish for the death of his neighbor Turkey, and Japan told him to "express it more mildly."
Lazy Comic Country
In the first strip ("This Exchange Continues Back and Forth for Another 15 times'), Greece attempted to learn how to speak Japanese from a guidebook and kept on consulting Japan on whether he was saying the phrases properly or not.
The second strip ("Greece and Japan's All-Too-Slow Paced World") had Greece saying to Japan that he'd like to be reincarnated as a cat and be free from GDP and trade deficits, but that he didn't think it would come true. Japan responded by placing a pair of cat ears on his head, and Greece tried to ask something along the lines of "Am I the child of a cat?" but Japan seemed to be confused by his imperfect Japanese. In the anime, he remarked, "Look. I am a big cat. Don't you want to scratch my belly?" to which Japan replied, "You need to seek professional help."The final strip ("Frequency") was based on the results of the 2005 Durex Global Sex Survey, where Greece placed #1 in the frequency of sex around the world and Japan placed last. After confirming the findings with Greece, Japan said that he envied his ability to have that much action as he considers himself to be an old man who lacks the energy to do it. Greece replied that Japan should learn how to enjoy sex more even if it might hurt at first, and the scene cut to a view outside of Japan's house with Japan screaming so loudly from inside that a nearby country, China, yelled at him to be quiet. In the next panel, a naked (or at least shirtless) Japan was seen bolting up in bed, yelling about how relieved he is that it was all a dream, even as Greece was shown to be sleeping next to him.
While walking together under an umbrella in the rain with Greece, Japan asked him why he was keeping his face turned away from him and Greece said that it was because the rain made his hair unnaturally curly and that he didn't want Japan to see his hair in that state. Japan couldn't see any difference between the way Greece's hair usually was and the way his hair looked now, and told him that his hair looked the same as usual and that he'd like to know how to tell his 'normal' and 'bed hair' apart. Greece appeared to be upset by his statements, until he recalled something France once said about "humiliation play" and wondered out loud if this was what was happening right now.
In an omake of sorts, Japan was stated to be feeling down afterwards for some reason and to have become delighted when he found the hair iron he had bought from America and buried in his cabinets when it had failed to make any noticeable effect on his (already straight) hair.
In "Soon Already," Japan and Greece went on a shopping trip to find a present for America's upcoming birthday. Greece showed Japan some possible gifts, but Japan said that they wouldn't make good ones for America, first telling him that a small stuffed cat wouldn't be a typical gift for a man and then saying "It's not about the size" when Greece showed him a much larger stuffed cat.
Greece asked Japan in "Super Angry Japan" if it was really true that no one had ever seen him get angry. The two agreed to try and get mad together; Greece easily succeeded by thinking about Turkey laughing at him, but Japan could only work himself up to a mildly dissatisfied state. Greece suggested that he think about wasting money to make himself even angrier, which was implied to have worked so well that a frantic Greece called up Turkey and asked to borrow a camera from him to take pictures of Japan in his 'super angry' state.
"Do your best, Japanese snacks!" was mainly about other countries trying out the Japanese snack "takenokoyama" and either finding it distasteful or not taking it seriously, with Greece as the only shown country who appeared to enjoy the snack, to the point of calling in his people and having them eat all of it.
Greece began telling Japan in "Giant Moussaka" that he made a movie about a moussaka turned enormous by aliens, but fell asleep before he could finish describing it to him.
In the Hetalia Fantasia CD, Japan briefly mentioned Greece as being unable to join in the RPG because Internet costs were too high at his place.
Greece's newest profile had a section about his relations with several other countries; one of them was Japan who was simply stated to be "Right here."
A May 2011 sketch of Greece in a chiton had a bonus sketch that showed him wearing cat ears too (in a possible reference to the Lazy Comic Country strip where Japan put cat ears on Greece's head) and holding up a piece of a cloth for a visibly flustered/embarrassed Japan to see.
In the Manga
In Volume 2 of the published manga, there was a chapter about Greece and Japan's relations that borrowed elements from several webcomic strips and integrated them with new ones. Their roles from Greece and Japan and the Cat Relation were reversed here, with Japan as the one visiting Greece's country and learning more about his culture and gods. Among the places Greece took Japan to were some of mother's ruins which he promptly fell asleep in, causing Japan to muse about what a mysterious person Greece was, the ancient temple for Zeus where he explained some of his gods to Japan, and the city of Sparta where he told Japan about how Spartans used to have naked examinations and offhandedly asked him if he'd like to try one, to which Japan gave a blunt "No."
Their mutual interest in cats and Greece's attempts to speak Japan's language were also shown, with Japan being introduced to Greece's cats and holding a conversation in Japanese with him. The latter scene in particular had Japan, having adopted Greece's alias of "Nekojirou-san" for him, answering his question of "Who does Nekojirou-san get along with?" with "His friend, Nekokichi-san" and then getting flustered when Greece asked him with a smile, "Am I Nekokichi-san?", finally hesitantly replying with "No comment."
Partway through Japan's tour of Greece, Turkey showed up and he and Greece got into an argument about which one Japan got along with more, with Turkey accusing Greece of trying to "invade" Japan and Greece telling him not to talk to Japan. When the two confronted Japan on which one of them he preferred, he avoided giving a proper answer, instead declaring that they should settle this with a game of "Rock, Paper, Scissors." It didn't seem to have settled anything since the next strip showed Greece and Turkey walking on opposite sides of Japan with Greece fuming and Turkey silently raging at Greece, at least until Japan tried to lighten the mood by showing them a trick with his thumb that left both of them gaping in shock at him.
The chapter concluded with a "Super Angry Japan" part nearly identical to the original webcomic strip.
There is some debate on whether Japan's exclamation that "It was all a dream!" at the end of Lazy Comic Country while he's naked or at least shirtless in bed with Greece is meant to be taken at face value or as a statement of denial about what really happened, but the general consensus is that it's most likely the latter. Either way, this strip is the only time so far in the webcomic series where sexual intercourse is heavily implied to have occurred between two characters, notable characteristics being that of Greece's slightly-askew hair and Japan's shirtlessness.
There are also some implications in other strips that Greece and Japan's interactions may have more than friendship behind them, the most notable being the Rainy Day strip where Greece and Japan share an umbrella, an action seen as romantic in Japanese culture. In the same strip, Greece wonders if "humiliation play" (apparently a reference to a sexual ploy) has something to do with Japan's statements about his hair that left him feeling hurt, which seems to indicate that Greece cares a lot about what Japan thinks of him and wouldn't be adverse to the possibility of Japan wanting to have sex with him at the very least, especially when coupled with him implicitly teaching Japan how to enjoy sex more in Lazy Comic Country. Similarly, Japan's actions in these same strips appear to imply that these feelings may not be entirely one-sided on Greece's part.
Many fans also see Greece and Turkey to be love rivals for Japan, as they get into arguments about which one of them Japan pays more attention to and the author's notes for Greece and Japan and the Cat Relation describe their relations as Greece→Japan←Turkey. While Japan avoids answering their question about which one of them he favors, the fact that he has been shown together with Greece much more often than with Turkey (in fact, Turkey has yet to receive a single strip with Japan that doesn't also include Greece) makes it highly likely that Japan is just being polite.
In general, Greece and Japan are portrayed in fanworks as having a highly stable and peaceful relationship due to their personalities being similar enough for them to rarely ever argue but also being different enough for them to patiently help each other overcome their faults, with Greece viewed as the one who can get Japan to relax and loosen up the most and Japan as the one who can get Greece to stay awake and focus the most.
- Greece and Japan's Loose Relations (Axis Powers Hetalia volume 2)
Webcomic: Extra Stories
- Greece and Japan and the Cat Relation
- Lazy Comic Country
- Rainy Day
- Do Your Best, Japanese Snacks!
Webcomic: Comic Diaries
- Comic Diary 6 ("Soon Already")
- Comic Diary 7 ("Giant Moussaka")
- Comic Diary 10 ("Super Angry Japan")