Japanese Avril?

Have you ever listened to your music player on shuffle mode and suddenly the next song sounds exactly like the last one and yet totally different? These two songs are absolutely different songs with different lyrics and different Languages! But you will notice immediately that the music and tune is strikingly similar. Of course there are a lot of Chinese-dubbed English songs and English-dubbed Chinese songs, but this is different! The titles and lyrics have so much difference.

5th single
「桜キッス」"Sakura Kiss"
Kawabe Chieco
2006.04.26 OUT
JPop News

Girlfriend (2007/3/21) Avril Lavigne Wiki Japan
From this fact, it is a high probability that Avril somehow listened to the Jap song and thought of a song with the same tune. But Avril listening to a JPop song?? How ridiculous is that?

On May 25, 2007, Lavigne, her co-songwriter Lukasz Gottwald, and her record label were sued by songwriters James Gangwer and Tommy Dunbar over claims that her song "Girlfriend" infringes on their 1979 song "I Wanna Be Your Boyfriend", originally performed by The Rubinoos.[30]
Wikipedia
And here, if Avril actually did listen to Sakura Kiss, her claim that she had "never heard the song in her life" would be irrefutable. Well, that would mean trespass of Kawabe Chieco's copyright however.

If it is true that Avril never heard both songs, then it would be very astonishing that 3 people could come to the exact same music and tune with different lyrics.

Is the world small or what?

In June 2007, Canadian singer-songwriter Chantal Kreviazuk, with whom Lavigne wrote the majority of her second album, Under My Skin, spoke to Performing Songwriter magazine about Lavigne's songwriting, saying, "I mean, Avril, songwriter? Avril doesn't really sit and write songs by herself or anything. Avril will also cross the ethical line and no one says anything. That's why I'll never work with her again. I sent her a song two years ago called 'Contagious', and I just saw the tracklisting to this album and there's a song called 'Contagious' on it – and my name's not on it. What do you do with that? See, I won't [call the lawyers], I'll just tell you. Art should not be subject to that kind of controversy."
Wikipedia

Or is the world just full of desperate people? ^^;
Truthfully, Avril's third album "The Best Damn Thing" didn't have as many good songs as her last two. It was a bit disappointing.