后街上的萌城少年后巷上的猫街少女
[hòu jiē shàng de méng chéng shăo nián hòu xiàng shàng de māo jiē shăo nǚ]
This translates to 'The naive boy from Behind Street in Dream City and the cat girl from Back Alley'. It's an elaborative title, likely used to convey a fantasy world, maybe related to certain youthful experiences, or characters one imagines living adventurous lives, filled with whimsy and romance.