积重难返

积 = 只 + 禾 : Joan of Arc (ji) and the cuttlefish (只) are preparing for bad times in front of the space station (Ø1). Together they are piling up (积) cereals (禾) so that they can always eat in times of need.

重 = 千 + 里 : Mnemonic symbol (from the shape of the character): this one looks like a space elevator. The two top strokes are the heavens, the two bottom strokes are the earth, and the part in between is the cabin (or climber) of the space elevator.

Chantal Chicken (chu) is working in the engine's kitchen ((e)ng2). Her job is to crush sunflower (里) seeds with a 1 kg weight (千) to get the kernels. Then she has to put the kernels into the cabin of a space elevator (重) to send them to outer space. This repeats (重) again and again day in, day out.

重 = 千 + 里 : Mnemonic symbol (from the shape of the character): this one looks like a space elevator. The two top strokes are the heavens, the two bottom strokes are the earth, and the part in between is the cabin (or climber) of the space elevator.

Julian Giant Squid (zhu) installed a space elevator (重) in the engine's bathroom ((e)ng4). For the maiden trip, and as a stress test, he loads one thousand (千) one kilogram weights (千) and decorates them with sun flowers (里) to celebrate the occasion.

难 = 又 + 隹 : Mnemonic symbol: a video game which is almost impossible to beat.

难 = 又 + 隹 : Just inside the anthill's kitchen, Napoleon and a sparrow are trying to beat an insanely difficult video game. After playing and failing all day long Napoleon finally loses his temper and crashes the game wearing two boxing gloves.

返 = 反 + 辶 : The protester (反) just entered the anthill (an3) wearing socks and gladiator sandals (辶). Frankenstein's Monster (f) protests loudly and tells the protester to go back (返) where he came from to either wear sandals and no socks, or socks and proper shoes.