test.py

import json

text = """```json
[
    ["Sunday", "Thursday"],
    ["two millions", "one million"],
    ["north", "east"],
    ["Japan", "UK"],
    ["Sunday", "Thursday"]
]
```
"""
def read_json(json_string) -> list[list[str]]:
    try:
        entities = json.loads(json_string)
        # Remove duplicates pair of entities
        unique_data = []
        for inner_list in entities:
            if inner_list not in unique_data:
                unique_data.append(inner_list)
        
        return unique_data

    except json.JSONDecodeError as e:
        print(f"Error decoding JSON: {e}")
        return []
print(read_json(text.replace("```json", "").replace("```", "")))