Fudged up the colouring but ahh well.
The lines included in this pic are the first few lines from the ending song in the 2003 anime. The song is titled 'Boy's Heart' so that's where the title for this pic came from because I don't have any imagination. Please note that the translations may not be accurate.
If you decide to download this for a closer look beware because it's a huge ass file.
Art by Me.
Sketched and coloured in SAI. Touch ups and effects in CS5.
Atom/Astro (C) Osamu Tezuka.