JSON nested array Sum values with key

Question

My table structure in MySQL

CREATE TABLE `user_data` (
  `id` int(11) NOT NULL,
  `user` varchar(100) NOT NULL,
  `data` longtext CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL CHECK (json_valid(`data`))
)

Table data

id	user	data
1	1	{"box1": {"books": 12, "pen": 100},"box2": {"books": 13, "pen": 200},"box4": {"books": 17, "pen": 300},"box5": {"books": 16, "pen": 300}}
2	5	{"box1": {"books": 12, "pen": 100},"box2": {"books": 13, "pen": 200},"box3": {"books": 14, "pen": 300}}

My expected results:

box	books	pen
box1	24	200
box2	26	400
box3	14	300
box4	17	300
box5	16	300

What is the MySQL select query to get this result?