With the advancement of vision-language models, image captioning has made significant progress, leading to the generation of more accurate and detailed descriptions. Current image captioning primarily focuses on describing the apparent visual characteristics, which are easily observed by most humans, but less helpful in real-world scenarios. When users seek a deeper understanding of visual content, they may be concerned with fine-grained categories, function properties, and other background knowledge, rather than merely appearances. Additionally, as users' interests vary, there is a growing demand for customizable content generation. To address these challenges, we propose the task of image narrative generation, which aims to produce knowledge-rich natural language responses for input images, customized to the user preference. Furthermore, we propose $T^4$, an image narrative generation model progressing through cascade steps: Tailor, reTrieve, Think, and Tell. Specifically, it takes the image and various types of prompts as input, and first refines or predicts potentially interesting queries that are tailored to the user expertise level. Subsequently, the model enriches contextual knowledge through retrieval-augmentation and employs chain-of-thoughts to decompose the generation process step by step, thereby telling an accurate and logically coherent image narrative. In addition, we construct the ImgNarr-23K dataset to support task training and evaluation. Experimental results demonstrate that the proposed approach generates image narrative that better satisfy user requirements, and achieves state-of-the-art performance in knowledge-based VQA tasks without additional finetuning. $T^4$ presents a promising solution for customized content generation in specialized domains.