Hourai Etealune, the mascot on the middle of the page is made by implementing Live2D via WebGL implementation. The image is drawn by my friend, and the rest is implemented by me (cutting, redrawing, filling empty gaps, animating, and WebGL implementation - with help of Live2D's SDK)
PS: If you're using mobile device with multitouch capability, the picture support pinch-to-zoom
Background for each button is courtesy of Google's Material Icons. The icons are repacked as a single stacked SVG vector file with some XML modification.