Rakuten/RakutenAI-7B-instruct · Very limited model response... am I doing something wrong?

Tried the following prompt and the response was worse than 'Mistral-7B-Instruct-v0.3' without the Japanese fine-tuning. Am I doing something wrong?

import requests

API_URL = "XXX"
headers = {
    "Accept" : "application/json",
    "Authorization": "Bearer YYY",
    "Content-Type": "application/json" 
}

def query(payload):
    response = requests.post(API_URL, headers=headers, json=payload)
    return response.json()

system_prompt = "You are a Japanese language teacher. Your task is to draft a beginner-level Japanese roleplay for making a restaurant reservation, focusing on specifying any dietary restrictions or special requests. Output the dialogue in JSON format with only the following keys: 'Japanese' and 'speaker'. "
prompt = "Draft a beginner-level Japanese roleplay to help me practice making a restaurant reservation, focusing on specifying any dietary restrictions or special requests. Use real-life examples."

msg = "<s> [INST] "+system_prompt+" \n "+prompt+" [/INST]"

output = query({
    "inputs": msg,
    "parameters": {
        "top_k": 50,
        "top_p": 0.95,
        "temperature": 0.7,
        "max_new_tokens": 1024
    }
})

print(output)