Where do you find shinx in Pokemon HeartGold?

Answer 1

My story:

One time, i caught a Shinx in the Sinnoh region. I wanted to start again in the Johto region, but, you see, no pets were allowed on the ferry. I got a Chikorita, but it just didn't feel the same. And, no Shinx to be viewed around the Johto region. A while after... i met an old friend from Sinnoh in the Pokemon Center. He said ''Go back, get your Shinx, and bring it to me. I will give it to you once you're at a Pokemon Center in the Johto region.''

Conclusion:

Catch a Shinx on Diamond, Pearl or Platinum, give it to a friend, and your friend'll (?) give it to you.

My second story:

soon after a found out from another friend that there is another way of catch another shinx in Heartgold and Soulsilver. He told me that in the following places you can find one whilst listening to Sinnoh Sound:National Park20%20%20%at level: 10, 12While playing Sinnoh SoundRoute 120%20%20%at level: 2, 3While playing Sinnoh SoundRoute 1120%20%20%at level: 14, 15While playing Sinnoh SoundRoute 1420%20%20%at level: 23, 25While playing Sinnoh SoundRoute 1520%20%20%at level: 23, 25While playing Sinnoh SoundRoute 1620%20%20%at level: 26, 28While playing Sinnoh SoundRoute 1720%20%20%at level: 28, 29While playing Sinnoh SoundRoute 1820%20%20%at level: 26, 28While playing Sinnoh SoundRoute 220%20%20%at level: 3, 5While playing Sinnoh SoundRoute 2920%20%20%at level: 2, 3While playing Sinnoh SoundRoute 320%20%20%at level: 5, 8While playing Sinnoh SoundRoute 3320%20%20%at level: 6, 6While playing Sinnoh SoundRoute 3620%20%20%at level: 12, 13While playing Sinnoh SoundRoute 3720%20%20%at level: 13, 15While playing Sinnoh SoundRoute 3820%20%20%at level: 16, 16While playing Sinnoh SoundRoute 3920%20%20%at level: 16, 16While playing Sinnoh SoundRoute 4620%20%20%at level: 3, 2While playing Sinnoh SoundRoute 520%20%20%at level: 13, 14While playing Sinnoh SoundRoute 720%20%20%at level: 17, 18While playing Sinnoh SoundRoute 820%20%20%at level: 17, 15While playing Sinnoh Sound
Wait til sinnoh sound comes on you're pokegear then fly to cherrygrove city and go out to the grass and you'll find one.