```json
{
    "no": ["no"],
    "yes": ["yes"]
}
```

Based on the feature description, the feature "default" indicates whether the client has credit in default. The possible values for this feature are "no" and "yes". In the given task, we are trying to determine if the client subscribes to a term deposit or not.

From the analysis, it can be observed that the clients with "no" value for the feature "default" are the ones who do not have credit in default and are less likely to subscribe to a term deposit. On the other hand, the clients with "yes" value for the feature "default" are the ones who have credit in default and may or may not subscribe to a term deposit.

Since the feature "default" has only two possible values, "no" and "yes", and we know that both values are present for the target classes ("no" and "yes"), we include these values in the dictionary.